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3. Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1

Author

Mazzanti, A, Guz, D, Trancuccio, A, Pagan, E, Kukavica, D, Chargeishvili, T, Olivetti, N, Biernacka, E, Sacilotto, L, Sarquella-Brugada, G, Campuzano, O, Nof, E, Anastasakis, A, Sansone, V, Jimenez-Jaimez, J, Cruz, F, Sanchez-Quinones, J, Hernandez-Afonso, J, Fuentes, M, Sredniawa, B, Garoufi, A, Andrsova, I, Izquierdo, M, Marinov, R, Danon, A, Exposito-Garcia, V, Garcia-Fernandez, A, Munoz-Esparza, C, Ortiz, M, Zienciuk-Krajka, A, Tavazzani, E, Monteforte, N, Bloise, R, Marino, M, Memmi, M, Napolitano, C, Zorio, E, Monserrat, L, Bagnardi, V, Priori, S, Mazzanti A., Guz D., Trancuccio A., Pagan E., Kukavica D., Chargeishvili T., Olivetti N., Biernacka E. K., Sacilotto L., Sarquella-Brugada G., Campuzano O., Nof E., Anastasakis A., Sansone V. A., Jimenez-Jaimez J., Cruz F., Sanchez-Quinones J., Hernandez-Afonso J., Fuentes M. E., Sredniawa B., Garoufi A., Andrsova I., Izquierdo M., Marinov R., Danon A., Exposito-Garcia V., Garcia-Fernandez A., Munoz-Esparza C., Ortiz M., Zienciuk-Krajka A., Tavazzani E., Monteforte N., Bloise R., Marino M., Memmi M., Napolitano C., Zorio E., Monserrat L., Bagnardi V., Priori S. G., Mazzanti, A, Guz, D, Trancuccio, A, Pagan, E, Kukavica, D, Chargeishvili, T, Olivetti, N, Biernacka, E, Sacilotto, L, Sarquella-Brugada, G, Campuzano, O, Nof, E, Anastasakis, A, Sansone, V, Jimenez-Jaimez, J, Cruz, F, Sanchez-Quinones, J, Hernandez-Afonso, J, Fuentes, M, Sredniawa, B, Garoufi, A, Andrsova, I, Izquierdo, M, Marinov, R, Danon, A, Exposito-Garcia, V, Garcia-Fernandez, A, Munoz-Esparza, C, Ortiz, M, Zienciuk-Krajka, A, Tavazzani, E, Monteforte, N, Bloise, R, Marino, M, Memmi, M, Napolitano, C, Zorio, E, Monserrat, L, Bagnardi, V, Priori, S, Mazzanti A., Guz D., Trancuccio A., Pagan E., Kukavica D., Chargeishvili T., Olivetti N., Biernacka E. K., Sacilotto L., Sarquella-Brugada G., Campuzano O., Nof E., Anastasakis A., Sansone V. A., Jimenez-Jaimez J., Cruz F., Sanchez-Quinones J., Hernandez-Afonso J., Fuentes M. E., Sredniawa B., Garoufi A., Andrsova I., Izquierdo M., Marinov R., Danon A., Exposito-Garcia V., Garcia-Fernandez A., Munoz-Esparza C., Ortiz M., Zienciuk-Krajka A., Tavazzani E., Monteforte N., Bloise R., Marino M., Memmi M., Napolitano C., Zorio E., Monserrat L., Bagnardi V., and Priori S. G.

Abstract

Background: Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. Objectives: This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. Methods: Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. Results: We enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). Conclusions: Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1.

Published
2020

4. Unexpected Risk Profile of a Large Pediatric Population With Brugada Syndrome

Author

Mazzanti, A, Ovics, P, Shauer, A, Mameli, S, Marino, M, Bloise, R, Monteforte, N, Raimondo, C, Maltret, A, Napolitano, C, Bagnardi, V, Priori, S, Mazzanti A., Ovics P., Shauer A., Mameli S., Marino M., Bloise R., Monteforte N., Raimondo C., Maltret A., Napolitano C., Bagnardi V., Priori S. G., Mazzanti, A, Ovics, P, Shauer, A, Mameli, S, Marino, M, Bloise, R, Monteforte, N, Raimondo, C, Maltret, A, Napolitano, C, Bagnardi, V, Priori, S, Mazzanti A., Ovics P., Shauer A., Mameli S., Marino M., Bloise R., Monteforte N., Raimondo C., Maltret A., Napolitano C., Bagnardi V., and Priori S. G.

Published
2019

5. Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1

Author

Mazzanti, A. Guz, D. Trancuccio, A. Pagan, E. Kukavica, D. Chargeishvili, T. Olivetti, N. Biernacka, E.K. Sacilotto, L. Sarquella-Brugada, G. Campuzano, O. Nof, E. Anastasakis, A. Sansone, V.A. Jimenez-Jaimez, J. Cruz, F. Sánchez-Quiñones, J. Hernandez-Afonso, J. Fuentes, M.E. Średniawa, B. Garoufi, A. Andršová, I. Izquierdo, M. Marinov, R. Danon, A. Expósito-García, V. Garcia-Fernandez, A. Muñoz-Esparza, C. Ortíz, M. Zienciuk-Krajka, A. Tavazzani, E. Monteforte, N. Bloise, R. Marino, M. Memmi, M. Napolitano, C. Zorio, E. Monserrat, L. Bagnardi, V. Priori, S.G.

Abstract

Background: Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. Objectives: This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. Methods: Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. Results: We enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). Conclusions: Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1. © 2020

Published
2020

12. Efficacy and Limitations of Quinidine in Patients with Brugada Syndrome

Author

Mazzanti, A, Tenuta, E, Marino, M, Pagan, E, Morini, M, Memmi, M, Colombi, B, Tibollo, V, Frassoni, S, Curcio, A, Raimondo, C, Maltret, A, Monteforte, N, Bloise, R, Napolitano, C, Bellazzi, R, Bagnardi, V, Priori, S, Mazzanti, Andrea, Tenuta, Elisavietta, Marino, Maira, Pagan, Eleonora, Morini, Massimo, Memmi, Mirella, Colombi, Barbara, Tibollo, Valentina, Frassoni, Samuele, Curcio, Antonio, Raimondo, Cristina, Maltret, Alice, Monteforte, Nicola, Bloise, Raffaella, Napolitano, Carlo, Bellazzi, Riccardo, Bagnardi, Vincenzo, Priori, Silvia G., Mazzanti, A, Tenuta, E, Marino, M, Pagan, E, Morini, M, Memmi, M, Colombi, B, Tibollo, V, Frassoni, S, Curcio, A, Raimondo, C, Maltret, A, Monteforte, N, Bloise, R, Napolitano, C, Bellazzi, R, Bagnardi, V, Priori, S, Mazzanti, Andrea, Tenuta, Elisavietta, Marino, Maira, Pagan, Eleonora, Morini, Massimo, Memmi, Mirella, Colombi, Barbara, Tibollo, Valentina, Frassoni, Samuele, Curcio, Antonio, Raimondo, Cristina, Maltret, Alice, Monteforte, Nicola, Bloise, Raffaella, Napolitano, Carlo, Bellazzi, Riccardo, Bagnardi, Vincenzo, and Priori, Silvia G.

Abstract

Background Quinidine at high dose is suggested as antiarrhythmic treatment in patients with Brugada Syndrome (BrS), but its efficacy to prevent life-threatening arrhythmic events (LAE) in this population is unproven and its use limited by frequent side effects. We assessed whether low-dose quinidine in patients with BrS reduces the following: (1) the occurrence of LAEs at follow-up, as compared to no therapy, in a population of both high-risk survivors of LAE and lower risk patients asymptomatic for LAEs and (2) the arrhythmic burden in the high-risk group of cardiac arrest survivors. Methods We compared the clinical course of 53 patients with BrS treated with quinidine to that of 441 untreated controls, matched by sex, age, symptoms, and the duration of observation. Furthermore, we calculated the annual incidence of LAE off-quinidine and on-quinidine in 123 patients with BrS who were cardiac arrest survivors. Results Fifty-three patients with BrS (89% males, median age 39.8 years) received quinidine (439±115 mg/d) for 5.0±3.7 years. Therapy was stopped in 3 cases (6%) for side effects. Quinidine reduced by 26% the risk of experiencing an LAE in cases versus controls (hazard ratio, 0.74; 95% CI, 0.22-2.48; P=0.62). Furthermore, in 27 of 123 patients with BrS symptomatic for LAEs who were treated for 7.0±3.5 years, the annual rate of LAEs decreased from 14.7% while off-quinidine to 3.9% while on-quinidine (P=0.03). Of note, recurrent LAEs were recorded in 4 (15%) cardiac arrest survivors while on-quinidine. Conclusions We demonstrated for the first time in the long-term that low-dose quinidine reduces recurrent LAEs in patients with BrS who had already survived an LAE, with few side effects. Remarkably, 15% of patients symptomatic for LAEs experience recurrent life-threatening arrhythmias while on-treatment, suggesting that quinidine cannot replace implantable defibrillators in high-risk subjects. Visual Overview A visual overview is available for this article.

Published
2019

15. Arrhythmogenic Right Ventricular Cardiomyopathy: Clinical Course and Predictors of Arrhythmic Risk

Author

Mazzanti, A, Ng, K, Faragli, A, Maragna, R, Chiodaroli, E, Orphanou, N, Monteforte, N, Memmi, M, Gambelli, P, Novelli, V, Bloise, R, Catalano, O, Moro, G, Tibollo, V, Morini, M, Bellazzi, R, Napolitano, C, Priori, S., BAGNARDI, VINCENZO, Mazzanti, A, Ng, K, Faragli, A, Maragna, R, Chiodaroli, E, Orphanou, N, Monteforte, N, Memmi, M, Gambelli, P, Novelli, V, Bloise, R, Catalano, O, Moro, G, Tibollo, V, Morini, M, Bellazzi, R, Napolitano, C, Bagnardi, V, and Priori, S

Subjects
implantable cardioverter-defibrillator, athlete, ventricular tachycardia, genetic, sudden cardiac death
Abstract

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading cause of sudden cardiac death, but its progression over time and predictors of arrhythmias are still being defined. Objectives This study sought to describe the clinical course of ARVC and occurrence of life-threatening arrhythmic events (LAE) and cardiovascular mortality; identify risk factors associated with increased LAE risk; and define the response to therapy. Methods We determined the clinical course of 301 consecutive patients with ARVC using the Kaplan-Meier method adjusted to avoid the bias of delayed entry. Predictors of LAE over 5.8 years of follow-up were determined with Cox multivariable analysis. Treatment efficacy was assessed comparing LAE rates during matched time intervals. Results A first LAE occurred in 1.5 per 100 person-years between birth and age 20 years, in 4.0 per 100 person-years between ages 21 and 40 years, and in 2.4 per 100 person-years between ages 41 and 60 years. Cumulative probability of a first LAE at follow-up was 14% at 5 years, 23% at 10 years, and 30% at 15 years. Higher risk of LAE was predicted by atrial fibrillation (hazard ratio [HR]: 4.38; p = 0.002), syncope (HR: 3.36; p < 0.001), participation in strenuous exercise after the diagnosis (HR: 2.98; p = 0.028), hemodynamically tolerated sustained monomorphic ventricular tachycardia (HR: 2.19; p = 0.023), and male sex (HR: 2.49; p = 0.012). No difference was observed in the occurrence of LAE before and after treatment with amiodarone, beta-blockers, sotalol, or ablation. A total of 81 patients received an implantable cardioverter-defibrillator, 34 were successfully defibrillated. Conclusions The high risk of life-threatening arrhythmias in patients with ARVC spans from adolescence to advanced age, reaching its peak between ages 21 and 40 years. Atrial fibrillation, syncope, participation in strenuous exercise after the diagnosis of ARVC, hemodynamically tolerated sustained monomorphic ventricular tachycardia, and male sex predicted lethal arrhythmias at follow-up. The lack of efficacy of antiarrhythmic therapy and the life-saving role of the implantable cardioverter-defibrillator highlight the importance of risk stratification for patient management.

Published
2016

16. Interplay Between Genetic Substrate, QTc Duration, and Arrhythmia Risk in Patients With Long QT Syndrome

Author

Mazzanti, A, Maragna, R, Vacanti, G, Monteforte, N, Bloise, R, Marino, M, Braghieri, L, Gambelli, P, Memmi, M, Pagan, E, Morini, M, Malovini, A, Ortiz, M, Sacilotto, L, Bellazzi, R, Monserrat, L, Napolitano, C, Bagnardi, V, Priori, S, Priori, SG, Mazzanti, A, Maragna, R, Vacanti, G, Monteforte, N, Bloise, R, Marino, M, Braghieri, L, Gambelli, P, Memmi, M, Pagan, E, Morini, M, Malovini, A, Ortiz, M, Sacilotto, L, Bellazzi, R, Monserrat, L, Napolitano, C, Bagnardi, V, Priori, S, and Priori, SG

Abstract

Background: Long QT syndrome (LQTS) is a common inheritable arrhythmogenic disorder, often secondary to mutations in the KCNQ1, KCNH2, and SCN5A genes. The disease is characterized by a prolonged ventricular repolarization (QTc interval) that confers susceptibility to life-threatening arrhythmic events (LAEs). Objectives: This study sought to create an evidence-based risk stratification scheme to personalize the quantification of the arrhythmic risk in patients with LQTS. Methods: Data from 1,710 patients with LQTS followed up for a median of 7.1 years (interquartile range [IQR]: 2.7 to 13.4 years) were analyzed to estimate the 5-year risk of LAEs based on QTc duration and genotype and to assess the antiarrhythmic efficacy of beta-blockers. Results: The relationship between QTc duration and risk of events was investigated by comparison of linear and cubic spline models, and the linear model provided the best fit. The 5-year risk of LAEs while patients were off therapy was then calculated in a multivariable Cox model with QTc and genotype considered as independent factors. The estimated risk of LAEs increased by 15% for every 10-ms increment of QTc duration for all genotypes. Intergenotype comparison showed that the risk for patients with LQT2 and LTQ3 increased by 130% and 157% at any QTc duration versus patients with LQT1. Analysis of response to beta-blockers showed that only nadolol reduced the arrhythmic risk in all genotypes significantly compared with no therapy (hazard ratio: 0.38; 95% confidence interval: 0.15 to 0.93; p = 0.03). Conclusions: The study provides an estimator of risk of LAEs in LQTS that allows a granular estimate of 5-year arrhythmic risk and demonstrate the superiority of nadolol in reducing the risk of LAEs in LQTS

Published
2018

18. Hydroquinidine Prevents Life-Threatening Arrhythmic Events in Patients With Short QT Syndrome

Author

Mazzanti, A, Maragna, R, Vacanti, G, Kostopoulou, A, Marino, M, Monteforte, N, Bloise, R, Underwood, K, Tibollo, V, Pagan, E, Napolitano, C, Bellazzi, R, Bagnardi, V, Priori, S, Priori, SG, Mazzanti, A, Maragna, R, Vacanti, G, Kostopoulou, A, Marino, M, Monteforte, N, Bloise, R, Underwood, K, Tibollo, V, Pagan, E, Napolitano, C, Bellazzi, R, Bagnardi, V, Priori, S, and Priori, SG

Abstract

Background Short QT syndrome (SQTS) is a rare and life-threatening arrhythmogenic syndrome characterized by abbreviated repolarization. Hydroquinidine (HQ) prolongs the QT interval in SQTS patients, although whether it reduces cardiac events is currently unknown. Objectives This study investigated whether long-term treatment with HQ reduces the occurrence of life-threatening arrhythmic events (LAE) (cardiac arrest or sudden cardiac death) in SQTS patients. Methods In this cohort study on consecutive SQTS patients, 2 analyses were performed: 1) a matched-period analysis for the occurrence of LAE in 17 SQTS patients who received long-term HQ; and 2) a comparison of the annual incidence of LAE off- and on-HQ in 16 SQTS patients who survived a cardiac arrest. Results A total of 17 patients (82% male, age 29 ± 3 years, QTc before treatment 331 ± 3 ms) received HQ therapy (584 ± 53 mg/day). Therapy was stopped in 2 cases (12%) due to gastrointestinal intolerance, and 15 patients continued treatment for 6 ± 1 year. QTc prolongation was observed in all patients (by 60 ± 6 ms; p < 0.001). We compared the occurrence of LAE during 6 ± 1 years before and after HQ, observing that patients on HQ experienced a reduction in both the rate of LAE from 40% to 0% (p = 0.03) and the number of LAE per patient from 0.73 ± 0.3 to 0 (p = 0.026). Furthermore, the annual rate of LAE in the 16 patients with a previous cardiac arrest dropped from 12% before HQ to 0 on therapy (p = 0.028). Conclusions We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS. In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects.

Published
2017

20. Gene-specific therapy with mexiletine reduces arrhythmic events in patients with long QT syndrome type 3

Author

Mazzanti, A, Maragna, R, Faragli, A, Monteforte, N, Bloise, R, Memmi, M, Novelli, V, Baiardi, P, Bagnardi, V, Etheridge, S, Napolitano, C, Priori, S, Priori, S., BAGNARDI, VINCENZO, Mazzanti, A, Maragna, R, Faragli, A, Monteforte, N, Bloise, R, Memmi, M, Novelli, V, Baiardi, P, Bagnardi, V, Etheridge, S, Napolitano, C, Priori, S, Priori, S., and BAGNARDI, VINCENZO

Abstract

Background Long QT syndrome type 3 (LQT3) is a lethal disease caused by gain-of-function mutations in the SCN5A gene, coding for the alpha-subunit of the sodium channel NaV1.5. Mexiletine is used to block late sodium current and to shorten QT interval in LQT3 patients. Objectives The aim of this study was to determine whether mexiletine prevents arrhythmic events (arrhythmic syncope, aborted cardiac arrest, or sudden cardiac death) in LQT3 patients. Methods The endpoint of this retrospective cohort study, which studied consecutive LQT3 patients who were referred to our center and treated with mexiletine, was to evaluate the antiarrhythmic efficacy of mexiletine by comparing the number of arrhythmic events per patient and the annual rate of arrhythmic events during observation periods of equal duration before and after the beginning of therapy with mexiletine. Results The study population comprised 34 LQT3 patients, 19 (56%) of whom were male. The median age at beginning of treatment with mexiletine was 22 years, and median QTc interval before therapy 509 ms. The median duration of oral mexiletine therapy was 36 months, at an average daily dose of 8 ± 0.5 mg/kg. Mexiletine significantly shortened QTc (by 63 ± 6 ms; p < 0.0001) and reduced the percentage of patients with arrhythmic events (from 22% to 3%; p = 0.031), the mean number of arrhythmic events per patient (from 0.43 ± 0.17 to 0.03 ± 0.03; p = 0.027), and the annual rate of arrhythmic events (from 10.3% to 0.7%; p = 0.0097). Conclusions Besides shortening QTc interval, mexiletine caused a major reduction of life-threatening arrhythmic events in LQT3 patients, thus representing an efficacious therapeutic strategy.

Published
2016

21. Efficacy of automatic mode switching in DDR mode pacemakers: the most 2 study

Author

SANTOMAURO, MAURIZIO, CHIARIELLO, MASSIMO, Ottaviano L, Borrelli A, Galasso G, Duilio C, Monteforte N, Padeletti L, Montenero AS, Andrew P, Santomauro, Maurizio, Ottaviano, L, Borrelli, A, Galasso, G, Duilio, C, Monteforte, N, Padeletti, L, Montenero, A, Andrew, P, and Chiariello, Massimo

Published
2008

22. Efficacy of automatic mode switching in DDDR mode pacemakers: the most 2 study

Author

Santomauro M, Ottaviano L, Borrelli A, Duilio C, Monteforte N, Padeletti L, Montenero AS, Andrew P, GALASSO, GENNARO, CHIARIELLO, MASSIMO, Santomauro, M, Ottaviano, L, Borrelli, A, Galasso, Gennaro, Duilio, C, Monteforte, N, Padeletti, L, Montenero, A, Andrew, P, and Chiariello, Massimo

Abstract

BACKGROUND: Effective automatic mode switching (AMS) algorithms capable of detecting a range of supraventricular tachyarrhythmias is important given evidence of atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT) post-implantation of pacemakers. OBJECTIVES: The aim of the study was to assess the efficacy, defined as ability to detect a specific atrial rate and activate AMS, of five different AMS mechanisms during simulation of AF, AFL, and AT. MATERIALS AND METHODS: A total of 48 subjects (35 men, 13 women; mean age: 69 +/- 8 years) implanted with DDDR pacemakers utilizing five different AMS mechanisms (mean atrial rate, rate cut-off, complex 'fallback' algorithm, retriggerable atrial refractory period, and physiological band 'beat-to-beat') were tested using an external electronic device that simulated the occurrence of supraventricular tachyarrhythmias. AF, AFL, and AT were simulated by delivering low voltage pulse trains at 350, 250 and 160 beats/min, respectively. RESULTS: Mean efficacy for all AMS mechanisms was 81% [range: 57% to 100%] at 350 beats/min, 81% [range: 57-100%] at 250 beats/min, and 79% [range: 57-100%] at 160 beats/min. The AMS mechanisms that yielded 100% efficacy were the rate cut-off and physiological band 'beat-to-beat.' CONCLUSION: Not all AMS algorithms are equally efficacious at detecting atrial arrhythmias and subsequently activating AMS. Our results suggest that the most efficacious AMS algorithms are those that use rate cut-off and physiological band 'beat-to-beat' to detect supraventricular tachyarrhythmias.

Published
2008

23. Left ventricular pacing in patients with heart failure: evaluation study with Fourier analysis of radionuclide ventriculography

Author

Santomauro, M., Pace, L., Duilio, C., Ottaviano, L., Borrelli, A., Ferro, A., Monteforte, N., Alberto Cuocolo, Salvatore, M., Chiariello, M., Santomauro, M., Pace, L., Duilio, C., Ottaviano, L., Borrelli, A., Ferro, A., Monteforte, N., Cuocolo, A., Salvatore, M., and Chiariello, M.

Subjects
Cardiomyopathy, Dilated, Male, Congestive heart failure, Pacemaker, Artificial, Bundle-Branch Block, Cardiac Pacing, Artificial, Biventricular pacing, Gated Blood-Pool Imaging, Stroke Volume, Middle Aged, Fourier analysis, Defibrillators, Implantable, Ventricular Dysfunction, Left, Humans, Aged, Follow-Up Studies
Abstract

Background. In order to correct the activation, contraction, and relaxation asynchronism, multisite biventricular stimulation has been proposed as a non-pharmacological alternative for the treatment of patients with congestive heart failure (CHF) NYHA class II-III-IV, resistant to maximal drug therapy and with a QRS duration > 120 ms. Fourier analysis appears a feasible technique for the quantitative and non-invasive evaluation of the inter- and intraventricular conduction delays. The aim of our study was to evaluate the usefulness of Fourier analysis when estimating the electromechanical resynchronization in CHF biventricular paced patients and to follow up these patients. Methods. Forty-five male patients (mean age 64 ± 5 years) with severe drug-refractory CHF, were submitted to radionuclide ventriculography 14 ± 7 days, 24 and 36 months after the implantation of a biventricular pacemaker, in order to assess left ventricular ejection fraction using Fourier analysis of the right and left ventricular phase images. Each patient was examined during spontaneous sinus rhythm, P-synchronous right ventricle and P-synchronous biventricular pacing. Results. Fourteen days after biventricular pacemaker implantation, QRS duration decreased from 170 ± 25 to 147 ± 25 ms (p < 0.01), left ventricular ejection fraction increased from 24 ± 6 to 31 ± 9% (p < 0.005), while standard deviation of the left ventricular phase decreased from 53 ± 6 to 35 ± 9% (p < 0.0005). Similar results were obtained at 24 and 36 months. Conclusions. Biventricular pacing appears to be associated with shortening of QRS duration and an improvement in NYHA class and left ventricular ejection fraction in CHF patients with inter- and intraventricular conduction delays as assessed at Fourier analysis radionuclide ventriculography. © 2004 CEPI Srl.

Published
2004

34. Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1

Author

Eyal Nof, Fernando E.S. Cruz, Victor Expósito-García, Luciana Sacilotto, Andrea Mazzanti, Jessica Sánchez-Quiñones, Elżbieta Katarzyna Biernacka, Esther Zorio, Deni Kukavica, Carmen Muñoz-Esparza, Julio Hernandez-Afonso, Elisa Tavazzani, Oscar Campuzano, Asaf Danon, Juan Jiménez-Jáimez, Martín Ortiz, Tekla Chargeishvili, Lorenzo Monserrat, Agnieszka Zienciuk-Krajka, Aristides Anastasakis, Carlo Napolitano, Eleonora Pagan, Maira Marino, Dmitri Guz, Amaya Garcia-Fernandez, Mirella Memmi, Beata Średniawa, Natália Olivetti, Valeria A. Sansone, Rumen Marinov, Georgia Sarquella-Brugada, Maite Izquierdo, Nicola Monteforte, Raffaella Bloise, María Eugenia Fuentes, Irena Andršová, Vincenzo Bagnardi, Silvia G. Priori, Alessandro Trancuccio, Anastasia Garoufi, Mazzanti, A, Guz, D, Trancuccio, A, Pagan, E, Kukavica, D, Chargeishvili, T, Olivetti, N, Biernacka, E, Sacilotto, L, Sarquella-Brugada, G, Campuzano, O, Nof, E, Anastasakis, A, Sansone, V, Jimenez-Jaimez, J, Cruz, F, Sanchez-Quinones, J, Hernandez-Afonso, J, Fuentes, M, Sredniawa, B, Garoufi, A, Andrsova, I, Izquierdo, M, Marinov, R, Danon, A, Exposito-Garcia, V, Garcia-Fernandez, A, Munoz-Esparza, C, Ortiz, M, Zienciuk-Krajka, A, Tavazzani, E, Monteforte, N, Bloise, R, Marino, M, Memmi, M, Napolitano, C, Zorio, E, Monserrat, L, Bagnardi, V, and Priori, S

Subjects
Male, Databases, Factual, Amiodarone, 030204 cardiovascular system & hematology, Sudden cardiac death, Electrocardiography, 0302 clinical medicine, Interquartile range, genetics, 030212 general & internal medicine, Child, sudden cardiac death, genetics, inherited arrhythmias, KCNJ2, life-threatening arrhythmic events, Andersen Syndrome, Muscle Weakness, Hazard ratio, Middle Aged, 3. Good health, Defibrillators, Implantable, Natural history, Child, Preschool, Risk stratification, Cohort, Female, Cardiology and Cardiovascular Medicine, Anti-Arrhythmia Agents, inherited arrhythmias, medicine.drug, Adult, medicine.medical_specialty, Adolescent, Adrenergic beta-Antagonists, Risk Assessment, sudden cardiac death, Syncope, life- threatening arrhythmic events, 03 medical and health sciences, Young Adult, Andersen–Tawil syndrome, Internal medicine, medicine, Humans, Genetic Testing, KCNJ2, Potassium Channels, Inwardly Rectifying, KCNJ2, genetics, inherited arrhythmias, life-threatening arrhythmic events, sudden cardiac death, business.industry, Infant, Arrhythmias, Cardiac, medicine.disease, life-threatening arrhythmic events, Death, Sudden, Cardiac, Mutation, Tachycardia, Ventricular, business
Abstract

BACKGROUND Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. OBJECTIVES This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. METHODS Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. RESULTS We enrolled 118 patients with ATS1 from 57 families (age 23 +/- 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). CONCLUSIONS Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1. (C) 2020 Published by Elsevier on behalf of the American College of Cardiology Foundation.

Published
2019

35. Efficacy and Limitations of Quinidine in Patients With Brugada Syndrome

Author

Andrea Mazzanti, Riccardo Bellazzi, Eleonora Pagan, Cristina Raimondo, Massimo Morini, Elisavietta Tenuta, Alice Maltret, Nicola Monteforte, Raffaella Bloise, Mirella Memmi, Barbara Colombi, Maira Marino, Vincenzo Bagnardi, Carlo Napolitano, Antonio Curcio, Samuele Frassoni, Valentina Tibollo, Silvia G. Priori, Mazzanti, A, Tenuta, E, Marino, M, Pagan, E, Morini, M, Memmi, M, Colombi, B, Tibollo, V, Frassoni, S, Curcio, A, Raimondo, C, Maltret, A, Monteforte, N, Bloise, R, Napolitano, C, Bellazzi, R, Bagnardi, V, and Priori, S

Subjects
Quinidine, medicine.medical_specialty, business.industry, 030204 cardiovascular system & hematology, medicine.disease, sudden cardiac death, Sudden cardiac death, cardiac arrhythmia, 03 medical and health sciences, Antiarrhythmic drug, 0302 clinical medicine, Physiology (medical), Internal medicine, Cardiology, Medicine, Brugada syndrome, In patient, 030212 general & internal medicine, Cardiology and Cardiovascular Medicine, business, quinidine, medicine.drug
Abstract

Background:Quinidine at high dose is suggested as antiarrhythmic treatment in patients with Brugada Syndrome (BrS), but its efficacy to prevent life-threatening arrhythmic events (LAE) in this population is unproven and its use limited by frequent side effects. We assessed whether low-dose quinidine in patients with BrS reduces the following: (1) the occurrence of LAEs at follow-up, as compared to no therapy, in a population of both high-risk survivors of LAE and lower risk patients asymptomatic for LAEs and (2) the arrhythmic burden in the high-risk group of cardiac arrest survivors.Methods:We compared the clinical course of 53 patients with BrS treated with quinidine to that of 441 untreated controls, matched by sex, age, symptoms, and the duration of observation. Furthermore, we calculated the annual incidence of LAE off-quinidine and on-quinidine in 123 patients with BrS who were cardiac arrest survivors.Results:Fifty-three patients with BrS (89% males, median age 39.8 years) received quinidine (439±115 mg/d) for 5.0±3.7 years. Therapy was stopped in 3 cases (6%) for side effects. Quinidine reduced by 26% the risk of experiencing an LAE in cases versus controls (hazard ratio, 0.74; 95% CI, 0.22–2.48;P=0.62). Furthermore, in 27 of 123 patients with BrS symptomatic for LAEs who were treated for 7.0±3.5 years, the annual rate of LAEs decreased from 14.7% while off-quinidine to 3.9% while on-quinidine (P=0.03). Of note, recurrent LAEs were recorded in 4 (15%) cardiac arrest survivors while on-quinidine.Conclusions:We demonstrated for the first time in the long-term that low-dose quinidine reduces recurrent LAEs in patients with BrS who had already survived an LAE, with few side effects. Remarkably, 15% of patients symptomatic for LAEs experience recurrent life-threatening arrhythmias while on-treatment, suggesting that quinidine cannot replace implantable defibrillators in high-risk subjects.

Published
2019

36. Unexpected Risk Profile of a Large Pediatric Population With Brugada Syndrome

Author

Stefano Mameli, Carlo Napolitano, Cristina Raimondo, Maira Marino, Paz Ovics, Alice Maltret, Ayelet Shauer, Silvia G. Priori, Andrea Mazzanti, Nicola Monteforte, Raffaella Bloise, Vincenzo Bagnardi, Mazzanti, A, Ovics, P, Shauer, A, Mameli, S, Marino, M, Bloise, R, Monteforte, N, Raimondo, C, Maltret, A, Napolitano, C, Bagnardi, V, and Priori, S

Subjects
Male, Pediatrics, medicine.medical_specialty, Adolescent, MEDLINE, 030204 cardiovascular system & hematology, Risk profile, Risk Assessment, 03 medical and health sciences, Electrocardiography, 0302 clinical medicine, CARDIAC THERAPY, Risk Factors, medicine, Humans, 030212 general & internal medicine, Child, Brugada syndrome, Brugada Syndrome, business.industry, Patient Selection, Clinical course, Follow up studies, Arrhythmias, Cardiac, medicine.disease, Heart Arrest, Patient Care Management, Italy, Female, Symptom Assessment, Cardiology and Cardiovascular Medicine, business, Pediatric population, Follow-Up Studies
Abstract

The clinical course of Brugada syndrome (BrS) in children and adolescents is incompletely defined due to the rarity of the phenotype in the first decades of life. In 2007, Probst et al. [(1)][1] reported the outcome of 30 pediatric patients with 3 years of follow-up, who experienced a 3% annual

Published
2018

37. Gene-Specific Therapy With Mexiletine Reduces Arrhythmic Events in Patients With Long QT Syndrome Type 3

Author

Paola Baiardi, Riccardo Maragna, Andrea Mazzanti, Susan P. Etheridge, Valeria Novelli, Mirella Memmi, Nicola Monteforte, Raffaella Bloise, Vincenzo Bagnardi, Silvia G. Priori, Alessandro Faragli, Carlo Napolitano, Mazzanti, A, Maragna, R, Faragli, A, Monteforte, N, Bloise, R, Memmi, M, Novelli, V, Baiardi, P, Bagnardi, V, Etheridge, S, Napolitano, C, and Priori, S

Subjects
0301 basic medicine, Male, Administration, Oral, LQTS, long QT syndrome, 030204 cardiovascular system & hematology, Sudden cardiac death, Electrocardiography, 0302 clinical medicine, Retrospective Studie, Heart Rate, Medicine, Child, SCN5A, Original Investigation, medicine.diagnostic_test, Medicine (all), Long QT Syndrome, Treatment Outcome, Anesthesia, Cardiology, beta-blocker, Female, Cardiology and Cardiovascular Medicine, Human, medicine.drug, sodium channel, Adult, medicine.medical_specialty, Adolescent, medicine.drug_class, Long QT syndrome, Mexiletine, QT interval, sudden cardiac death, Follow-Up Studie, Young Adult, 03 medical and health sciences, Internal medicine, Heart rate, Humans, Beta blocker, business.industry, LQT3, long QT syndrome type 3, Retrospective cohort study, Genetic Therapy, medicine.disease, CI, confidence interval, 030104 developmental biology, Voltage-Gated Sodium Channel Blocker, ECG, electrocardiogram, mutation, business
Abstract

Background Long QT syndrome type 3 (LQT3) is a lethal disease caused by gain-of-function mutations in the SCN5A gene, coding for the alpha-subunit of the sodium channel NaV1.5. Mexiletine is used to block late sodium current and to shorten QT interval in LQT3 patients. Objectives The aim of this study was to determine whether mexiletine prevents arrhythmic events (arrhythmic syncope, aborted cardiac arrest, or sudden cardiac death) in LQT3 patients. Methods The endpoint of this retrospective cohort study, which studied consecutive LQT3 patients who were referred to our center and treated with mexiletine, was to evaluate the antiarrhythmic efficacy of mexiletine by comparing the number of arrhythmic events per patient and the annual rate of arrhythmic events during observation periods of equal duration before and after the beginning of therapy with mexiletine. Results The study population comprised 34 LQT3 patients, 19 (56%) of whom were male. The median age at beginning of treatment with mexiletine was 22 years, and median QTc interval before therapy 509 ms. The median duration of oral mexiletine therapy was 36 months, at an average daily dose of 8 ± 0.5 mg/kg. Mexiletine significantly shortened QTc (by 63 ± 6 ms; p < 0.0001) and reduced the percentage of patients with arrhythmic events (from 22% to 3%; p = 0.031), the mean number of arrhythmic events per patient (from 0.43 ± 0.17 to 0.03 ± 0.03; p = 0.027), and the annual rate of arrhythmic events (from 10.3% to 0.7%; p = 0.0097). Conclusions Besides shortening QTc interval, mexiletine caused a major reduction of life-threatening arrhythmic events in LQT3 patients, thus representing an efficacious therapeutic strategy.

Published
2016
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38. Interplay Between Genetic Substrate, QTc Duration, and Arrhythmia Risk in Patients With Long QT Syndrome

Author

Nicola Monteforte, Mirella Memmi, Raffaella Bloise, Alberto Malovini, Carlo Napolitano, Vincenzo Bagnardi, L. Braghieri, Silvia G. Priori, Massimo Morini, Gaetano Vacanti, Eleonora Pagan, Andrea Mazzanti, Patrick Gambelli, Luciana Sacilotto, Lorenzo Monserrat, Martín Ortiz, Riccardo Maragna, Maira Marino, Riccardo Bellazzi, Ministero della Salute (Italia), Mazzanti, A, Maragna, R, Vacanti, G, Monteforte, N, Bloise, R, Marino, M, Braghieri, L, Gambelli, P, Memmi, M, Pagan, E, Morini, M, Malovini, A, Ortiz, M, Sacilotto, L, Bellazzi, R, Monserrat, L, Napolitano, C, Bagnardi, V, Priori, S, and Italian Ministry of Health

Subjects
Male, medicine.medical_specialty, congenital, hereditary, and neonatal diseases and abnormalities, Genotype, Long QT syndrome, 030204 cardiovascular system & hematology, QT interval, Risk Assessment, sudden cardiac death, Cohort Studies, 03 medical and health sciences, 0302 clinical medicine, Interquartile range, Nadolol, Internal medicine, medicine, Humans, 030212 general & internal medicine, cardiovascular diseases, Proportional hazards model, business.industry, life-threatening arrhythmic event, Hazard ratio, Heart, medicine.disease, inherited arrhythmia, Confidence interval, Long QT Syndrome, beta-blocker, Cardiology, Female, genetic, Cardiology and Cardiovascular Medicine, Risk assessment, business, medicine.drug
Abstract

Long QT syndrome (LQTS) is a common inheritable arrhythmogenic disorder, often secondary to mutations in the KCNQ1, KCNH2, and SCN5A genes. The disease is characterized by a prolonged ventricular repolarization (QTc interval) that confers susceptibility to life-threatening arrhythmic events (LAEs). This study sought to create an evidence-based risk stratification scheme to personalize the quantification of the arrhythmic risk in patients with LQTS. Data from 1,710 patients with LQTS followed up for a median of 7.1 years (interquartile range [IQR]: 2.7 to 13.4 years) were analyzed to estimate the 5-year risk of LAEs based on QTc duration and genotype and to assess the antiarrhythmic efficacy of beta-blockers. The relationship between QTc duration and risk of events was investigated by comparison of linear and cubic spline models, and the linear model provided the best fit. The 5-year risk of LAEs while patients were off therapy was then calculated in a multivariable Cox model with QTc and genotype considered as independent factors. The estimated risk of LAEs increased by 15% for every 10-ms increment of QTc duration for all genotypes. Intergenotype comparison showed that the risk for patients with LQT2 and LQT3 increased by 130% and 157% at any QTc duration versus patients with LQT1. Analysis of response to beta-blockers showed that only nadolol reduced the arrhythmic risk in all genotypes significantly compared with no therapy (hazard ratio: 0.38; 95% confidence interval: 0.15 to 0.93; p = 0.03). The study provides an estimator of risk of LAEs in LQTS that allows a granular estimate of 5-year arrhythmic risk and demonstrate the superiority of nadolol in reducing the risk of LAEs in LQTS. This work was supported by the Ricerca Corrente funding scheme of the Italian Ministry of Health. Dr. Ortiz has received personal fees from Health in Code, SL. Dr. Monserrat is a shareholder in Health in Code, SL. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Sí

Published
2018

39. Hydroquinidine Prevents Life-Threatening Arrhythmic Events in Patients With Short QT Syndrome

Author

Silvia G. Priori, Riccardo Bellazzi, Riccardo Maragna, Gaetano Vacanti, Andrea Mazzanti, Valentina Tibollo, Katherine Underwood, Carlo Napolitano, Maira Marino, Anna Kostopoulou, Nicola Monteforte, Eleonora Pagan, Raffaella Bloise, Vincenzo Bagnardi, Italian Ministry of Health, Mazzanti, A, Maragna, R, Vacanti, G, Kostopoulou, A, Marino, M, Monteforte, N, Bloise, R, Underwood, K, Tibollo, V, Pagan, E, Napolitano, C, Bellazzi, R, Bagnardi, V, Priori, S, and Ministero della Salute (Italia)

Subjects
0301 basic medicine, Adult, Male, medicine.medical_specialty, Adolescent, 030204 cardiovascular system & hematology, arrhythmia, QT interval, sudden cardiac death, Follow-Up Studie, Sudden cardiac death, 03 medical and health sciences, Electrocardiography, Young Adult, 0302 clinical medicine, Heart Conduction System, Heart Rate, Internal medicine, Heart rate, medicine, Humans, Survival rate, short QT syndrome, drug repurposing, medicine.diagnostic_test, business.industry, Incidence, Short QT syndrome, Arrhythmias, Cardiac, medicine.disease, Quinidine, Survival Rate, 030104 developmental biology, Death, Sudden, Cardiac, hydroquinidine, Italy, Anti-Arrhythmia Agent, Ventricular fibrillation, Ventricular Fibrillation, Cardiology, Female, Electrical conduction system of the heart, Cardiology and Cardiovascular Medicine, business, Anti-Arrhythmia Agents, Human, Follow-Up Studies
Abstract

Short QT syndrome (SQTS) is a rare and life-threatening arrhythmogenic syndrome characterized by abbreviated repolarization. Hydroquinidine (HQ) prolongs the QT interval in SQTS patients, although whether it reduces cardiac events is currently unknown. This study investigated whether long-term treatment with HQ reduces the occurrence of life-threatening arrhythmic events (LAE) (cardiac arrest or sudden cardiac death) in SQTS patients. In this cohort study on consecutive SQTS patients, 2 analyses were performed: 1) a matched-period analysis for the occurrence of LAE in 17 SQTS patients who received long-term HQ; and 2) a comparison of the annual incidence of LAE off- and on-HQ in 16 SQTS patients who survived a cardiac arrest. A total of 17 patients (82% male, age 29 ± 3 years, QTc before treatment 331 ± 3 ms) received HQ therapy (584 ± 53 mg/day). Therapy was stopped in 2 cases (12%) due to gastrointestinal intolerance, and 15 patients continued treatment for 6 ± 1 year. QTc prolongation was observed in all patients (by 60 ± 6 ms; p < 0.001). We compared the occurrence of LAE during 6 ± 1 years before and after HQ, observing that patients on HQ experienced a reduction in both the rate of LAE from 40% to 0% (p = 0.03) and the number of LAE per patient from 0.73 ± 0.3 to 0 (p = 0.026). Furthermore, the annual rate of LAE in the 16 patients with a previous cardiac arrest dropped from 12% before HQ to 0 on therapy (p = 0.028). We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS. In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects. This work was supported by the Ricerca Corrente Funding scheme of the Italian Ministry of Health. Dr. Bellazzi is a shareholder of Biomeris; and is a stakeholder of Engenome. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Pedro Brugada, MD, served as Guest Editor for this paper. Sí

Published
2017

40. Role of CACNA1C in Brugada syndrome: Prevalence and phenotype of probands referred for genetic testing.

Author

Novelli V, Memmi M, Malovini A, Mazzanti A, Liu N, Yanfei R, Bongianino R, Denegri M, Monteforte N, Bloise R, Morini M, and Napolitano C

Subjects
Calcium Channels, L-Type genetics, Genetic Testing, Humans, Mutation, NAV1.5 Voltage-Gated Sodium Channel genetics, Phenotype, Prevalence, Brugada Syndrome diagnosis, Brugada Syndrome epidemiology, Brugada Syndrome genetics
Abstract

Background: Evidence for the role of the CACNA1C gene, which encodes for the α-subunit of the cardiac L-type calcium channel CaV1.2, as a cause of the BrS3 variant of Brugada syndrome (BrS) is contradictory., Objective: The purpose of this study was to define in a large BrS cohort the yield of molecular screening and to test whether appropriate patient selection could improve clinical utility., Methods: A total of 709 patients were included in this study. BrS probands (n = 563, consecutively referred) underwent CACNA1C sequencing. Two matched cohorts where defined: discovery cohort (n = 200) and confirmation cohort (n = 363). In addition, the clinical phenotypes of a matched SCN5A-positive BrS cohort (n = 146) were included for comparative genotype-phenotype correlation., Results: In the discovery cohort, we identified 11 different rare variants in 9 patients; 10 of the variants (5%) were considered potentially causative based on their frequency in the general population. However, American College of Medical Genetics criteria were unable to classify the majority (80%) of them, which eventually were labeled as variants of unknown significance (VUS). Functional studies revealed a loss of function for 9 variants, pointing to a prevalence of CACNA1C causative variants in 4% of the discovery cohort. Genotype-phenotype correlation showed that pathogenic variants are significantly more frequent in patients with shorter QTc (12.9% vs 2.2% in patients with QTc <390 ms)., Conclusion: CACNA1C is an infrequent but definitive cause of BrS typically associated with short QT. Functional studies are highly relevant to improve variant interpretation., (Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Published
2022
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41. Outcomes of Patients With Catecholaminergic Polymorphic Ventricular Tachycardia Treated With β-Blockers.

Author

Mazzanti A, Kukavica D, Trancuccio A, Memmi M, Bloise R, Gambelli P, Marino M, Ortíz-Genga M, Morini M, Monteforte N, Giordano U, Keegan R, Tomasi L, Anastasakis A, Davis AM, Shimizu W, Blom NA, Santiago DJ, Napolitano C, Monserrat L, and Priori SG

Subjects
Adolescent, Adrenergic beta-Antagonists therapeutic use, Adult, Child, Cohort Studies, Electrocardiography, Female, Humans, Male, Prospective Studies, Ryanodine Receptor Calcium Release Channel genetics, Syncope, Young Adult, Nadolol therapeutic use, Tachycardia, Ventricular diagnosis
Abstract

Importance: Patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) may experience life-threatening arrhythmic events (LTAEs) despite β-blocker treatment. Further complicating management, the role of implantable cardioverter defibrillator (ICD) in CPVT is debated., Objective: To investigate the long-term outcomes of patients with RYR2 CPVT treated with β-blockers only and the cost to benefit ratio of ICD., Design, Settings, and Participants: This prospective cohort study conducted from January 1988 to October 2020 with a mean (SD) follow-up of 9.4 (7.5) years included patients who were referred to the Molecular Cardiology Clinics of ICS Maugeri Hospital, Pavia, Italy. Participants included consecutive patients with CPVT who were carriers of a pathogenic or likely pathogenic RYR2 variant with long-term clinical follow-up., Exposures: Treatment with selective and nonselective β-blocker only and ICD implant when indicated., Main Outcome and Measures: The main outcome was the occurrence of the first LTAE while taking a β-blocker. LTAE was defined as a composite of 3 hard end points: sudden cardiac death, aborted cardiac arrest, and hemodynamically nontolerated ventricular tachycardia., Results: The cohort included 216 patients with RYR2 CPVT (121 of 216 female [55%], median [IQR] age 14, [9-30] years). During a mean (SD) follow-up of 9.4 (7.5) years taking β-blockers only, 28 of 216 patients (13%) experienced an LTAE (annual rate, 1.9%; 95% CI, 1.3-2.7). In multivariable analysis, experiencing either an LTAE (hazard ratio [HR], 3.3; 95% CI, 1.2-8.9; P = .02) or syncope before diagnosis (HR, 4.5; 95% CI, 1.8-11.1; P = .001) and carrying a C-terminal domain variant (HR, 18.1; 95% CI, 4.1-80.8; P < .001) were associated with an increased LTAE risk during β-blocker therapy only. The risk of LTAE among those taking selective β-blockers vs nadolol was increased 6-fold (HR, 5.8; 95% CI, 2.1-16.3; P = .001). Conversely, no significant difference was present between propranolol and nadolol (HR, 1.8; 95% CI, 0.4-7.3; P = .44). An ICD was implanted in 79 of 216 patients (37%) who were followed up for a mean (SD) of 8.6 (6.3) years. At the occurrence of LTAE, ICD carriers were more likely to survive (18 of 18 [100%]) than non-ICD carriers (6 of 10 [60%]; P = .01)., Conclusions and Relevance: In this cohort study, selective β-blockers were associated with a higher risk of LTAE as compared with nadolol. Independently from treatment, LTAE and syncope before diagnosis and C-terminal domain variants identified patients at higher risk of β-blocker failure, and the ICD was associated with reduced mortality in high-risk patients with CPVT.

Published
2022
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42. Association of Hydroxychloroquine With QTc Interval in Patients With COVID-19.

Author

Mazzanti A, Briani M, Kukavica D, Bulian F, Marelli S, Trancuccio A, Monteforte N, Manciulli T, Morini M, Carlucci A, Viggiani G, Cannata F, Negri S, Bloise R, Memmi M, Gambelli P, Carbone A, Molteni M, Bianchini R, Salgarello R, Sozzi S, De Cata P, Fanfulla F, Ceriana P, Locatelli C, Napolitano C, Chiovato L, Tomasi L, Stefanini GG, Condorelli G, and Priori SG

Subjects
Aged, Aged, 80 and over, COVID-19 epidemiology, COVID-19 virology, Electrocardiography methods, Female, Humans, Long QT Syndrome epidemiology, Male, Middle Aged, Hydroxychloroquine pharmacology, Long QT Syndrome drug therapy, COVID-19 Drug Treatment
Published
2020
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43. Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1.

Author

Mazzanti A, Guz D, Trancuccio A, Pagan E, Kukavica D, Chargeishvili T, Olivetti N, Biernacka EK, Sacilotto L, Sarquella-Brugada G, Campuzano O, Nof E, Anastasakis A, Sansone VA, Jimenez-Jaimez J, Cruz F, Sánchez-Quiñones J, Hernandez-Afonso J, Fuentes ME, Średniawa B, Garoufi A, Andršová I, Izquierdo M, Marinov R, Danon A, Expósito-García V, Garcia-Fernandez A, Muñoz-Esparza C, Ortíz M, Zienciuk-Krajka A, Tavazzani E, Monteforte N, Bloise R, Marino M, Memmi M, Napolitano C, Zorio E, Monserrat L, Bagnardi V, and Priori SG

Subjects
Adolescent, Adrenergic beta-Antagonists therapeutic use, Adult, Amiodarone administration & dosage, Amiodarone adverse effects, Andersen Syndrome genetics, Andersen Syndrome therapy, Anti-Arrhythmia Agents administration & dosage, Anti-Arrhythmia Agents adverse effects, Arrhythmias, Cardiac therapy, Child, Child, Preschool, Databases, Factual, Death, Sudden, Cardiac epidemiology, Defibrillators, Implantable, Electrocardiography, Female, Genetic Testing, Humans, Infant, Male, Middle Aged, Muscle Weakness etiology, Mutation, Potassium Channels, Inwardly Rectifying genetics, Syncope etiology, Syncope therapy, Tachycardia, Ventricular etiology, Tachycardia, Ventricular therapy, Young Adult, Andersen Syndrome complications, Arrhythmias, Cardiac etiology, Risk Assessment
Abstract

Background: Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported., Objectives: This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1., Methods: Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis., Results: We enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00)., Conclusions: Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1., (Copyright © 2020. Published by Elsevier Inc.)

Published
2020
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44. Unexpected Risk Profile of a Large Pediatric Population With Brugada Syndrome.

Author

Mazzanti A, Ovics P, Shauer A, Mameli S, Marino M, Bloise R, Monteforte N, Raimondo C, Maltret A, Napolitano C, Bagnardi V, and Priori SG

Subjects
Adolescent, Child, Electrocardiography methods, Female, Follow-Up Studies, Humans, Italy epidemiology, Male, Patient Selection, Risk Factors, Symptom Assessment methods, Symptom Assessment statistics & numerical data, Arrhythmias, Cardiac etiology, Arrhythmias, Cardiac therapy, Brugada Syndrome diagnosis, Brugada Syndrome epidemiology, Brugada Syndrome physiopathology, Brugada Syndrome therapy, Heart Arrest diagnosis, Heart Arrest prevention & control, Patient Care Management methods, Risk Assessment methods
Published
2019
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45. Interplay Between Genetic Substrate, QTc Duration, and Arrhythmia Risk in Patients With Long QT Syndrome.

Author

Mazzanti A, Maragna R, Vacanti G, Monteforte N, Bloise R, Marino M, Braghieri L, Gambelli P, Memmi M, Pagan E, Morini M, Malovini A, Ortiz M, Sacilotto L, Bellazzi R, Monserrat L, Napolitano C, Bagnardi V, and Priori SG

Subjects
Cohort Studies, Female, Genotype, Humans, Long QT Syndrome genetics, Male, Risk Assessment, Heart physiopathology, Long QT Syndrome physiopathology
Abstract

Background: Long QT syndrome (LQTS) is a common inheritable arrhythmogenic disorder, often secondary to mutations in the KCNQ1, KCNH2, and SCN5A genes. The disease is characterized by a prolonged ventricular repolarization (QTc interval) that confers susceptibility to life-threatening arrhythmic events (LAEs)., Objectives: This study sought to create an evidence-based risk stratification scheme to personalize the quantification of the arrhythmic risk in patients with LQTS., Methods: Data from 1,710 patients with LQTS followed up for a median of 7.1 years (interquartile range [IQR]: 2.7 to 13.4 years) were analyzed to estimate the 5-year risk of LAEs based on QTc duration and genotype and to assess the antiarrhythmic efficacy of beta-blockers., Results: The relationship between QTc duration and risk of events was investigated by comparison of linear and cubic spline models, and the linear model provided the best fit. The 5-year risk of LAEs while patients were off therapy was then calculated in a multivariable Cox model with QTc and genotype considered as independent factors. The estimated risk of LAEs increased by 15% for every 10-ms increment of QTc duration for all genotypes. Intergenotype comparison showed that the risk for patients with LQT2 and LQT3 increased by 130% and 157% at any QTc duration versus patients with LQT1. Analysis of response to beta-blockers showed that only nadolol reduced the arrhythmic risk in all genotypes significantly compared with no therapy (hazard ratio: 0.38; 95% confidence interval: 0.15 to 0.93; p = 0.03)., Conclusions: The study provides an estimator of risk of LAEs in LQTS that allows a granular estimate of 5-year arrhythmic risk and demonstrate the superiority of nadolol in reducing the risk of LAEs in LQTS., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Published
2018
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46. Hydroquinidine Prevents Life-Threatening Arrhythmic Events in Patients With Short QT Syndrome.

Author

Mazzanti A, Maragna R, Vacanti G, Kostopoulou A, Marino M, Monteforte N, Bloise R, Underwood K, Tibollo V, Pagan E, Napolitano C, Bellazzi R, Bagnardi V, and Priori SG

Subjects
Adolescent, Adult, Anti-Arrhythmia Agents administration & dosage, Arrhythmias, Cardiac complications, Arrhythmias, Cardiac physiopathology, Death, Sudden, Cardiac epidemiology, Death, Sudden, Cardiac etiology, Electrocardiography, Female, Follow-Up Studies, Heart Conduction System drug effects, Heart Conduction System physiopathology, Heart Rate drug effects, Humans, Incidence, Italy epidemiology, Male, Quinidine administration & dosage, Survival Rate trends, Ventricular Fibrillation complications, Ventricular Fibrillation epidemiology, Young Adult, Arrhythmias, Cardiac drug therapy, Death, Sudden, Cardiac prevention & control, Quinidine analogs & derivatives, Ventricular Fibrillation prevention & control
Abstract

Background: Short QT syndrome (SQTS) is a rare and life-threatening arrhythmogenic syndrome characterized by abbreviated repolarization. Hydroquinidine (HQ) prolongs the QT interval in SQTS patients, although whether it reduces cardiac events is currently unknown., Objectives: This study investigated whether long-term treatment with HQ reduces the occurrence of life-threatening arrhythmic events (LAE) (cardiac arrest or sudden cardiac death) in SQTS patients., Methods: In this cohort study on consecutive SQTS patients, 2 analyses were performed: 1) a matched-period analysis for the occurrence of LAE in 17 SQTS patients who received long-term HQ; and 2) a comparison of the annual incidence of LAE off- and on-HQ in 16 SQTS patients who survived a cardiac arrest., Results: A total of 17 patients (82% male, age 29 ± 3 years, QTc before treatment 331 ± 3 ms) received HQ therapy (584 ± 53 mg/day). Therapy was stopped in 2 cases (12%) due to gastrointestinal intolerance, and 15 patients continued treatment for 6 ± 1 year. QTc prolongation was observed in all patients (by 60 ± 6 ms; p < 0.001). We compared the occurrence of LAE during 6 ± 1 years before and after HQ, observing that patients on HQ experienced a reduction in both the rate of LAE from 40% to 0% (p = 0.03) and the number of LAE per patient from 0.73 ± 0.3 to 0 (p = 0.026). Furthermore, the annual rate of LAE in the 16 patients with a previous cardiac arrest dropped from 12% before HQ to 0 on therapy (p = 0.028)., Conclusions: We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS. In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Published
2017
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47. Arrhythmogenic Right Ventricular Cardiomyopathy: Clinical Course and Predictors of Arrhythmic Risk.

Author

Mazzanti A, Ng K, Faragli A, Maragna R, Chiodaroli E, Orphanou N, Monteforte N, Memmi M, Gambelli P, Novelli V, Bloise R, Catalano O, Moro G, Tibollo V, Morini M, Bellazzi R, Napolitano C, Bagnardi V, and Priori SG

Subjects
Adolescent, Adult, Arrhythmogenic Right Ventricular Dysplasia complications, Arrhythmogenic Right Ventricular Dysplasia epidemiology, Child, Child, Preschool, Death, Sudden, Cardiac epidemiology, Death, Sudden, Cardiac prevention & control, Defibrillators, Implantable, Disease Progression, Female, Follow-Up Studies, Humans, Incidence, Infant, Infant, Newborn, Italy epidemiology, Male, Middle Aged, Retrospective Studies, Risk Factors, Survival Rate trends, Time Factors, Young Adult, Arrhythmogenic Right Ventricular Dysplasia diagnosis, Death, Sudden, Cardiac etiology, Risk Assessment methods
Abstract

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading cause of sudden cardiac death, but its progression over time and predictors of arrhythmias are still being defined., Objectives: This study sought to describe the clinical course of ARVC and occurrence of life-threatening arrhythmic events (LAE) and cardiovascular mortality; identify risk factors associated with increased LAE risk; and define the response to therapy., Methods: We determined the clinical course of 301 consecutive patients with ARVC using the Kaplan-Meier method adjusted to avoid the bias of delayed entry. Predictors of LAE over 5.8 years of follow-up were determined with Cox multivariable analysis. Treatment efficacy was assessed comparing LAE rates during matched time intervals., Results: A first LAE occurred in 1.5 per 100 person-years between birth and age 20 years, in 4.0 per 100 person-years between ages 21 and 40 years, and in 2.4 per 100 person-years between ages 41 and 60 years. Cumulative probability of a first LAE at follow-up was 14% at 5 years, 23% at 10 years, and 30% at 15 years. Higher risk of LAE was predicted by atrial fibrillation (hazard ratio [HR]: 4.38; p = 0.002), syncope (HR: 3.36; p < 0.001), participation in strenuous exercise after the diagnosis (HR: 2.98; p = 0.028), hemodynamically tolerated sustained monomorphic ventricular tachycardia (HR: 2.19; p = 0.023), and male sex (HR: 2.49; p = 0.012). No difference was observed in the occurrence of LAE before and after treatment with amiodarone, beta-blockers, sotalol, or ablation. A total of 81 patients received an implantable cardioverter-defibrillator, 34 were successfully defibrillated., Conclusions: The high risk of life-threatening arrhythmias in patients with ARVC spans from adolescence to advanced age, reaching its peak between ages 21 and 40 years. Atrial fibrillation, syncope, participation in strenuous exercise after the diagnosis of ARVC, hemodynamically tolerated sustained monomorphic ventricular tachycardia, and male sex predicted lethal arrhythmias at follow-up. The lack of efficacy of antiarrhythmic therapy and the life-saving role of the implantable cardioverter-defibrillator highlight the importance of risk stratification for patient management., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Published
2016
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48. Clinical Presentation and Outcome of Brugada Syndrome Diagnosed With the New 2013 Criteria.

Author

Curcio A, Mazzanti A, Bloise R, Monteforte N, Indolfi C, Priori SG, and Napolitano C

Subjects
Action Potentials, Adult, Brugada Syndrome physiopathology, Brugada Syndrome therapy, Female, Heart Rate, Humans, Male, Middle Aged, Practice Guidelines as Topic, Predictive Value of Tests, Prognosis, Registries, Young Adult, Brugada Syndrome diagnosis, Electrocardiography standards, Heart Conduction System physiopathology
Abstract

Introduction: The 2013 HRS/EHRA/APHRS consensus statement recommends the use of V1 and V2 leads recorded in the second and third intercostal spaces (High-ICS) for diagnosis of Brugada syndrome (BrS) creating a new category of patients discovered only with modified leads. The clinical presentation and the arrhythmic risk in these patients are ill defined. This study was aimed at assessing the role of High-ICS in the analysis of BrS and the clinical profile of the patients diagnosed only when ECG leads are moved to upper intercostal spaces., Methods and Results: We searched our Brugada syndrome registry and identified 300 subjects (age 36 ± 13 years), without a diagnostic coved ST-segment elevation in conventional V1 -V3 leads, both at baseline and after provocative drug challenge. Sixty-four subjects (21.3%, mean age at last follow-up 42 ± 11 years) were diagnosed with High-ICS. Diagnosis was possible at baseline only in 4 subjects while in 60 it was made after drug challenge with sodium channel blockers. Three subjects (4.7%) with spontaneous abnormal ECG experienced cardiac events with an annual event rate (0.11%) superimposable to that of the low risk category of BrS diagnosed in standard leads., Conclusion: This study demonstrates that the use of new diagnostic criteria for BrS allows increasing the diagnostic yield by 20% and that the arrhythmic risk is low when BrS can be established only in High-ICS. We also show that the prognostic value of spontaneous ECG pattern is confirmed in this subgroup., (© 2016 Wiley Periodicals, Inc.)

Published
2016
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49. Gene-Specific Therapy With Mexiletine Reduces Arrhythmic Events in Patients With Long QT Syndrome Type 3.

Author

Mazzanti A, Maragna R, Faragli A, Monteforte N, Bloise R, Memmi M, Novelli V, Baiardi P, Bagnardi V, Etheridge SP, Napolitano C, and Priori SG

Subjects
Administration, Oral, Adolescent, Adult, Child, Female, Follow-Up Studies, Humans, Long QT Syndrome genetics, Long QT Syndrome physiopathology, Male, Retrospective Studies, Treatment Outcome, Voltage-Gated Sodium Channel Blockers administration & dosage, Young Adult, Electrocardiography, Genetic Therapy methods, Heart Rate drug effects, Long QT Syndrome therapy, Mexiletine administration & dosage
Abstract

Background: Long QT syndrome type 3 (LQT3) is a lethal disease caused by gain-of-function mutations in the SCN5A gene, coding for the alpha-subunit of the sodium channel NaV1.5. Mexiletine is used to block late sodium current and to shorten QT interval in LQT3 patients., Objectives: The aim of this study was to determine whether mexiletine prevents arrhythmic events (arrhythmic syncope, aborted cardiac arrest, or sudden cardiac death) in LQT3 patients., Methods: The endpoint of this retrospective cohort study, which studied consecutive LQT3 patients who were referred to our center and treated with mexiletine, was to evaluate the antiarrhythmic efficacy of mexiletine by comparing the number of arrhythmic events per patient and the annual rate of arrhythmic events during observation periods of equal duration before and after the beginning of therapy with mexiletine., Results: The study population comprised 34 LQT3 patients, 19 (56%) of whom were male. The median age at beginning of treatment with mexiletine was 22 years, and median QTc interval before therapy 509 ms. The median duration of oral mexiletine therapy was 36 months, at an average daily dose of 8 ± 0.5 mg/kg. Mexiletine significantly shortened QTc (by 63 ± 6 ms; p < 0.0001) and reduced the percentage of patients with arrhythmic events (from 22% to 3%; p = 0.031), the mean number of arrhythmic events per patient (from 0.43 ± 0.17 to 0.03 ± 0.03; p = 0.027), and the annual rate of arrhythmic events (from 10.3% to 0.7%; p = 0.0097)., Conclusions: Besides shortening QTc interval, mexiletine caused a major reduction of life-threatening arrhythmic events in LQT3 patients, thus representing an efficacious therapeutic strategy., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Published
2016
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50. Novel insight into the natural history of short QT syndrome.

Author

Mazzanti A, Kanthan A, Monteforte N, Memmi M, Bloise R, Novelli V, Miceli C, O'Rourke S, Borio G, Zienciuk-Krajka A, Curcio A, Surducan AE, Colombo M, Napolitano C, and Priori SG

Subjects
Adult, Arrhythmias, Cardiac epidemiology, Arrhythmias, Cardiac genetics, Arrhythmias, Cardiac metabolism, DNA Mutational Analysis, Ether-A-Go-Go Potassium Channels metabolism, Female, Follow-Up Studies, Gene Frequency, Humans, Incidence, Italy epidemiology, Male, Survival Rate trends, Time Factors, Young Adult, DNA genetics, Electrocardiography, Ether-A-Go-Go Potassium Channels genetics, Genetic Predisposition to Disease, Genetic Testing methods, Mutation
Abstract

Objectives: This study intends to gain further insights into the natural history, the yield of familial and genetic screening, and the arrhythmogenic mechanisms in the largest cohort of short QT syndrome (SQTS) patients described so far., Background: SQTS is a rare genetic disorder associated with life-threatening arrhythmias, and its natural history is incompletely ascertained., Methods: Seventy-three SQTS patients (84% male; age, 26 ± 15 years; corrected QT interval, 329 ± 22 ms) were studied, and 62 were followed for 60 ± 41 months (median, 56 months)., Results: Cardiac arrest (CA) was the most frequent presenting symptom (40% of probands; range, <1 month to 41 years). The rate of CA was 4% in the first year of life and 1.3% per year between 20 and 40 years; the probability of a first occurrence of CA by 40 years of age was 41%. Despite the male predominance, female patients had a risk profile superimposable to that of men (p = 0.49). The yield of genetic screening was low (14%), despite familial disease being present in 44% of kindreds. A history of CA was the only predictor of recurrences at follow-up (p < 0.0000001). Two patterns of onset of ventricular fibrillation were observed and were reproducible in patients with multiple occurrences of CA. Arrhythmias occurred mainly at rest., Conclusions: SQTS is highly lethal; CA is often the first manifestation of the disease with a peak incidence in the first year of life. Survivors of CA have a high CA recurrence rate; therefore, implantation of a defibrillator is strongly recommended in this group of patients., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Published
2014
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