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Background: Atrial fibrillation (AF) is a common complication in patients with hypertrophic cardiomyopathy (HCM) and may contribute to high cardiovascular morbidity and mortality. Therefore, it is important to assess parameters associated with AF in HCM patients., Hypothesis: The aim of the study was to evaluate AF prevalence in patients with HCM and to investigate risk factors for AF., Methods: Five hundred and forty-six HCM patients aged below 65 were included into analysis. Clinical and echocardiographic parameters were analyzed., Results: In 141 patients (25.8%) AF episodes were recorded. The following factors were identified as risk factors for AF in patients with HCM: age ≥ 45 years (OR 2.38, CI 1.40-4.05, P = 0.001), past history of presyncope or syncope (OR 2.25, CI 1.35-3.74, P = 0.002), non-sustained ventricular tachycardia (nsVT) (OR 2.70, CI 1.60-4.57, P < 0.001), left atrium diameter during first assessment (OR 1.065, CI 1.03-1.11, P = 0.001), left atrium diameter at the last assessment before AF occurrence (OR 1.10, CI 1.06-1.14, P < 0.001) and left ventricular ejection fraction at the last assessment before AF occurrence (CI 0.96, CI 0.94-0.98, P = 0.001)., Conclusions: We confirm that AF is a common complication for patients with HCM. Identification of patients with high risk for AF and implementation of preventive strategies may reduce AF occurrence and its complications., (© 2018 Wiley Periodicals, Inc.)

Background: Estimation of sudden cardiac death (SCD) risk is an integral part of clinical management of patients with hypertrophic cardiomyopathy (HCM). Identification of novel biomarkers of this disease can provide additional criteria for SCD risk stratification. Soluble suppression of tumourigenicity (sST2) and galectin-3 (Gal-3) are useful biomarkers for prognosis of heart failure (HF). Both of them appear to mediate cardiac fibrosis - an important pathogenetic process in HCM. Data about sST2 and Gal-3 usefulness in patients with HCM are limited., Aim: The aim of this study was to evaluate sST2 and Gal-3 as potential novel biomarkers for better risk stratification in hypertrophic cardiomyopathy., Methods: Serum sST2 and serum Gal-3 levels were measured in 57 patients with HCM and in 18 healthy controls. The patients with HCM underwent routine evaluation including medical history, physical examination, blood tests (including N-terminal pro-B-type natriuretic peptide [NT-proBNP] and high-sensitivity cardiac troponin T [hs-cTnT] measurements), 12-lead electrocardiography (ECG), 48-h Holter monitoring and two-dimensional (2D) echocardiography with the assessment of the maximal left ventricular wall thickness, left atrial diameter, maximal left ventricular outflow tract gradient, and left ventricular ejection fraction. Risk of SCD at five years according to HCM SCD-risk calculator was evaluated. The control group underwent ECG, 2D echocardiography, and NT-proBNP measurements to exclude asymptomatic heart disease., Results: Concentrations of sST2 and Gal-3 were significantly higher in patients with HCM than in controls (14.9 ± 5.8 ng/mL vs. 11.7 ± 3.3 ng/mL, p = 0.03 and 8.4 ng/mL [6.8-10.0] vs. 6.2 ng/mL [5.8-7.7], p = 0.005, respectively). Levels of sST2 and Gal-3 were considerably different in the New York Heart Association (NYHA) groups (p = 0.008, p = 0.009, respectively). Patients who presented non-sustained ventricular tachycardia (nsVT) on 48-h Holter monitoring had higher levels of sST2 (19.1 ng/mL [12.2-24.2] vs. 13.2 ng/mL [10.0-17.1], p = 0.02). There were no significant relationships between sST2 and Gal-3 levels and HCM SCD-risk, history of syncope presence, family history of SCD, and echocardio-graphic parameters., Conclusions: Gal-3 levels and sST2 levels were higher in patients with HCM than in the control group. There were significant differences in Gal-3 levels between NYHA classes, but no correlations between Gal-3 levels and other parameters were found. Apart from differences in sST2 levels between NYHA classes, we demonstrated higher levels of sST2 in patients with nsVT. These findings suggest that sST2 may be useful as an additional biomarker for better risk stratification in hypertrophic cardiomyopathy.

Background: The presence of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcome and the extent of LGE predicts the increased risk of sudden cardiac death (SCD). Limited data exist regarding the distribution of LGE. We attempted to verify whether the presence of LGE outside the interventricular insertion points carries additional risk for patients with HCM., Methods: In this prospective study, 328 patients with HCM, who underwent cardiac magnetic resonance (CMR) were enrolled. Five major risk factors for SCD were assessed in all patients. The median follow-up was 37 months., Results: LGE was detected in 226 (68.9%) patients. In 70 (21.3%) patients it was present only at the interventricular insertion points - LGE (+) group, while in 156 (47.6%) it was noted in other locations - LGE (++) group. Primary endpoint defined as SCD or appropriate implantable cardioverter-defibrillator intervention occurred in 14 (4.3%) patients, one in LGE (+) and 13 in LGE (++). In multivariable analysis including five traditional risk factors and left ventricular ejection fraction <50%, only the presence of LGE outside the insertion points was a significant predictor of SCD/aborted SCD (HR 10.01, 95% CI 1.21-83.86, p=0.033). The performance of the multivariable sudden cardiac death risk model was improved by the addition of LGE (++) to the traditional risk factors (likelihood ratio p=0.005). The Kaplan-Meier curves showed better event-free survival in the LGE (-) and LGE (+) patient groups compared to the LGE (++) group., Conclusions: In HCM patients, presence of LGE outside interventricular insertion points is associated with increased risk of sudden cardiac death or its equivalent as well as overall mortality. Cardiac fibrosis as a substrate for SCD in HCM may be identified on CMR and serve as an imaging biomarker of increased risk., (Copyright © 2016. Published by Elsevier Ltd.)

Background: Atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is generally associated with deterioration of the clinical status, functional capacity, and quality of life. It is also an independent risk factor for stroke and death. Studies evaluating the effectiveness of AF ablation in this cohort are relatively scant, have included relatively few patients, and their results are somewhat conflicting. Thus, the aim of this study was to assess the safety and efficacy of catheter ablation of AF in patients with HCM., Methods: Thirty patients (10 females; mean age 48.7 ± 11 years) with drug-refractory paroxysmal (n = 14), persistent (n = 7), or long-persistent (> 1 year; n = 9) AF were prospectively recruited into the study. Eleven patients were in New York Heart Association (NYHA) class I, 13 patients were in NYHA class II, and 6 patients were in NYHA class III. Mean atrial volume was 180 ± 47 mL, interventricular septum thickness was 20.5 ± 6.3 mm, and left atrial area was 29.8 ± 6.2 cm2. Ablation protocol was adjusted to the clinical and electrophysiological status of the patients. Pulmonary vein isolation and bidirectional cavo-tricuspid isthmus block were performed in all patients. In addition, left atrial linear lesions were created and complex fragmented atrial potentials were ablated in patients with persistent and long-persistent AF, as well as during repeated procedures., Results: At 12 months, stable sinus rhythm (SR) was present in 16 (53%) patients, significantly more frequently in patients with paroxysmal AF (71% in SR) compared to those with persistent (57.1% in SR) or long-persistent (22% in SR) AF. A significant reduction of AF burden was observed in 85.7% of patients with paroxysmal AF, 71.4% of patients with persistent AF, and 55.5% of patients with long-persistent AF. Single procedure success rate was 33% (10 patients), and repeat ablation procedures were performed in 13 patients. No periprocedural complications occurred. Thromboembolic events were noted in 2 patients with arrhythmia recurrence during the follow-up, including stroke in 1 patient and peripheral embolism in the other patient. In both these patients, heart failure worsening was observed during these events, and anticoagulation was inadequate in one of them. Five of 16 patients in whom stable SR was observed during the follow-up were off antiarrhythmic drug therapy at final evaluation. In the other 6 patients, antiarrhythmic drug therapy was continued due to ventricular arrhythmias. Successfully treated patients more often had paroxysmal AF (successful ablation: paroxysmal AF in 10 of 16 patients; unsuccessful ablation: paroxysmal AF in 4 of 14 patients; p = 0.009) and were younger (45 ± 11.5 years vs. 52.6 ± 9.2 years; p = 0.046). In addition, a trend toward a reduced need for cardioversion at the end of the procedure was also observed in these patients (3 patients in the successful ablation group vs. 8 patients in the unsuccessful ablation group; p = 0.056). In multivariate regression analysis, paroxysmal AF was the only independent predictor of a successful outcome., Conclusions: Catheter ablation of AF in patients with HCM is an effective and safe therapeutic option, particularly in patients with paroxysmal AF. Effectiveness of ablation is significantly smaller in patients with persistent AF and even more so in those with long-persistent AF. Repeated procedures were often necessary. Continued antiarrhythmic drug therapy is often required due to a significant degree of atrial remodelling.

The heart rate variability of 10 healthy males (age 26 - 4/+ 3 y) and 49 patients with hypertrophic cardiomyopathy (HCM) (25 males, 24 females, age 29.5 - 11.5/+ 10.5 y) was studied. We applied Kramers-Moyal expansion to extract the drift and diffusion terms of the Langevin equation for the RR interval time series. These terms may be used for a stochastic reconstruction of the time series and for description of the properties of heart rate variability. New parameters characterizing the diffusion term are proposed: the coefficients of the linear fit to the left (LCF) and right (RCF) branch of the dependence of the diffusion term on the rescaled heart rate. Relations of the new parameters to classical echocardiography parameters were studied. Using the relation between the difference LCF-RCF and the left ventricular systolic diameter, the HCM patients studied were divided into three groups. In addition, comparison of the properties of the heart rate variability in the HCM group with that obtained for the healthy young men showed that the parameter LCF-RCF may be treated as a measure of the effect of HCM on heart rate variability and may have diagnostic value.

Background: Percutaneous alcohol septal ablation (ASA) becomes an alternative option of treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). The procedure relieves left ventricular outflow tract obstruction, but produces a myocardial scar in patients who already have a substrate for life-threatening ventricular arrhythmia., Objectives: To examine the effect of ASA on the occurrence of non-sustained ventricular tachycardia (nsVT) on 24 h ambulatory Holter monitoring in HOCM patients., Methods: Sixty-one consecutive patients (34 males, mean age 48 years), who underwent ASA between 1997 and 2003 were analyzed. Holter recordings were performed in each patient before and after ablation., Results: Follow-up ranged from 60 to 125 months (median 116 months). The mean number of Holter recordings per patient was 2.7 (range 1-11) before and 8.3 (range 2-23) after ASA (p < 0.001). Non-sustained ventricular tachycardia occurred in 14 patients before and 27 patients after ASA (23 vs. 44%, p = 0.01). The percentage of Holter recordings with nsVT before and after ablation was similar (14.5 vs. 15.7%, p = 0.56, respectively). No difference was observed between the number of nsVT per Holter recording before and after ablation (0.21 vs. 0.24%, p = 0.65, respectively). The percentage of patients with nsVT after ASA was comparable to the proportion of patients with nsVT in a control group consisting of 705 patients with hypertrophic cardiomyopathy under follow-up at our institution (44.3 vs. 43.2%, p = 0.91). There was no significant difference in percentage of Holter recordings with nsVT with respect to sex, amount of alcohol used during ASA, peak creatine phosphokinase level, and gradient reduction at rest., Conclusion: Alcohol septal ablation affected neither the percentage of Holter recordings with nsVT nor the number of nsVT episodes per Holter recording among HOCM patients.

In hypertrophic cardiomyopathy (HCM) patients there is an increased risk of premature death, which can occur with little or no warning. Furthermore, classification for sudden cardiac death on patients with HCM is very difficult. The aim of our study was to improve the prognostic value of heart rate variability (HRV) in HCM patients, giving insight into changes of the autonomic nervous system. In this way, the suitability of linear and nonlinear measures was studied to assess the HRV. These measures were based on time-frequency representation (TFR) and on Shannon and Rényi entropies, and compared with traditional HRV measures. Holter recordings of 64 patients with HCM and 55 healthy subjects were analyzed. The HCM patients consisted of two groups: 13 high risk patients, after aborted sudden cardiac death (SCD); 51 low risk patients, without SCD. Five-hour RR signals, corresponding to the sleep period of the subjects, were considered for the analysis as a comparable standard situation. These RR signals were filtered in the three frequency bands: very low frequency band (VLF, 0-0.04 Hz), low frequency band (LF, 0.04-0.15 Hz) and high frequency band (HF, 0.15-0.45 Hz). TFR variables based on instantaneous frequency and energy functions were able to classify HCM patients and healthy subjects (control group). Results revealed that measures obtained from TFR analysis of the HRV better classified the groups of subjects than traditional HRV parameters. However, results showed that nonlinear measures improved group classification. It was observed that entropies calculated in the HF band showed the highest statistically significant levels comparing the HCM group and the control group, p-value < 0.0005. The values of entropy measures calculated in the HCM group presented lower values, indicating a decreasing of complexity, than those calculated from the control group. Moreover, similar behavior was observed comparing high and low risk of premature death, the values of the entropy being lower in high risk patients, p-value < 0.05, indicating an increase of predictability. Furthermore, measures from information entropy, but not from TFR, seem to be useful for enhanced risk stratification in HCM patients with an increased risk of sudden cardiac death.

This study examined ventricular repolarization before the onset of 37 episodes of nonsustained ventricular tachycardia (NSVT) in 26 untreated patients with hypertrophic cardiomyopathy (HCM). Fourteen episodes were recorded in patients with a history of cardiac arrest or patients who died suddenly during follow-up. The QT interval was measured beat-by-beat on 24-hour ambulatory electrocardiograms. Mean 24-hour, hourly QTc and QTc of the last 10 beats prior to NSVT, consisted of 4-50 cycles (mean 9 +/- 10), at the fastest rates of 100-175 beats/min (mean 122 +/- 22) were analyzed. NSVT was more prevalent during nighttime (23 episodes), than during daytime (14 episodes, P < 0.05). No significant differences were observed between mean 24-hour, mean hourly QTc during the hour with NSVT, and QTc of the last 10 cycles prior to onset of NSVT. QTc was significantly longer in patients with a history of sudden cardiac death (SCD) or who died suddenly during follow-up than in survivors. The 24-hour QT variability was higher in nonsurvivors than in survivors (-39 +/- 6 vs 33 +/- 6 ms, P = 0.03). Episodes of NSVT in untreated patients with hypertrophic cardiomyopathy were more frequent during the nighttime. The 24-hour QT variability was higher in nonsurvivors than in survivors.

The RT interval is a measure of the ventricular repolarization and is partially influenced by the sympathovagal balance. The analysis of the variation of the duration of the RT and RR intervals might bring new information about the arrhythmogenic vulnerability and autonomic imbalance. The RR signal and its spectral density (SD) are characterized by two different patterns during the sleep period. On the basis of this information, RT and RR sequences have been automatically classified into two patterns, R and N. In this work, we propose a methodology to define new variables that are able to distinguish patients with hypertrophic cardiomyopathy (HCM) who later developed sudden cardiac death (SCD) from HCM patients without such episode during the follow-up. These variables are based on the instantaneous frequency calculation using time-frequency representation of the RT and RR signals previously classified into R and N patterns. In this study, three spectral bands have been considered: low-frequency band (LF, 0-0.07 Hz), mid-frequency band (MF, 0.07-0.15 Hz), and high-frequency band (HF, 0.15-0.45 Hz). Then a suitable combination of mean energy and mean frequency of the RT and RR signals in the MF and HF bands has allowed HCM patients with SCD to be discriminated from HCM patients without SCD (P < 0.001)., (Copyright 2000 Academic Press.)