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A 77-year-old man with ischemic cardiomyopathy and a cardiac resynchronization therapy-defibrillator (CRT-D) device came to our attention due to incessant ventricular tachycardia and multiple implantable cardioverter defibrillator (ICD) shocks. An electrocardiogram showed non-sustained monomorphic ventricular tachycardias (NSVTs) constantly occurring after each biventricular stimulation. During an electrophysiological study, NSVTs reproducibly recurred only after right ventricular (RV) pacing; LV pacing did not induce any NSVTs.The activation map was consistent with a localized reentry at the interventricular septum, and a double exit; at the LV exit site, a single radiofrequency energy application immediately interrupted the occurrence of the NSVTs.Current evidence supports LV pacing to be pro-arrhythmogenic in few CRT patients. This unusual case shows that RV pacing during CRT could produce frequent ventricular arrhythmias and arrhythmic storm. Catheter ablation can be considered an effective therapeutic option, especially when CRT maintenance is highly advisable.

In patients with left ventricular assist device (LVAD), a minority of post-operative ventricular tachycardias (VTs) is caused by contact between the inflow cannula and the endocardium. Currently, electrophysiologic characteristics and pathologic features of this condition are lacking. We report on a case of a successfully ablated mechanical VT. After VT recurrence, heart transplantation took place. Pathologic observations were consistent with direct tissue injury and inflammation, eventually contributing to persisting arrhythmias. Radiofrequency catheter ablation can be a safe and effective option to treat arrhythmias caused by inflow cannula interference in the short term, although a high recurrence rate is expected.

BACKGROUND: Late gadolinium enhancement (LGE) assessed with cardiovascular magnetic resonance (CMR) correlates with ventricular arrhythmias and survival in patients with structural heart disease. Whether some LGE characteristics may specifically improve prediction of arrhythmic outcomes is unknown. HYPOTHESIS: We sought to evaluate scar characteristics assessed with CMR to predict implantable cardioverter‐defibrillator (ICD) interventions in dilated cardiomyopathy of different etiology. METHODS: 96 consecutive patients evaluated with CMR received an ICD. Biventricular volumes, ejection fraction, and myocardial LGE were evaluated. LGE was defined as “complex” (Cx‐LGE) in presence of ≥1 of the following: ischemic pattern, involving ≥2 different coronary territories; epicardial pattern; global endocardial pattern; and presence of ≥2 different patterns. The primary endpoint was occurrence of any appropriate ICD intervention. A composite secondary endpoint of cardiovascular death, cardiac transplantation, or ventricular assist device implantation was also considered. RESULTS: During a median follow‐up of 75 months, 30 and 25 patients reached the primary and secondary endpoints, respectively. Cx‐LGE was correlated with a worse primary endpoint survival (log‐rank P < 0.001). Cx‐LGE and right ventricular end‐diastolic volume were independently associated with the primary endpoint (HR: 3.22, 95% CI: 1.56–6.65, P = 0.002; and HR: 1.06, 95% CI: 1.00–1.12, P = 0.045, respectively), but not with the secondary endpoint. CONCLUSIONS: Cx‐LGE identified at CMR imaging seems promising as an independent and specific prognostic factor of ventricular arrhythmias requiring ICD therapy in dilated cardiomyopathy of different etiologies.

To investigate the clinical relevance of l-thyroxine (l-T(4)) substitution therapy in borderline hypothyroidism.To assess whether and to what extent administration of l-T(4) is able to modify systolic and diastolic function in patients with subclinical hypothyroidism and in subjects with autoimmune thyroiditis and normal serum TSH.We studied 26 patients with classical Hashimoto's thyroiditis [18 with increased serum TSH (3 mU/ml - Group A), and 8 with normal serum TSH (3 mU/ml) - Group B]; a third group (C) included 13 healthy controls. All subjects underwent Pulsed Wave Tissue Doppler Imaging (PWTDI) to accurately quantify the global and regional left ventricular function.In both groups A and B we confirmed a significant impairment of systolic ejection (p0.001 and p0.05, respectively), a delay in diastolic relaxation (p0.001 and p0.05, respectively) and a decrease in the compliance to the ventricular filling (p0.05). Administration of 50 microg/day of l-T(4) produced a progressive reduction of serum TSH (within the normal range) and normalization of all PWTDI parameters, which began after 6 months and finished after 12 months.Our data confirm previous evidence that subclinical hypothyroidism is associated with a cardiac dysfunction, even when this is very mild (i.e. with serum TSH still comprised in the normal range), and show that these abnormalities are reversible with l-T(4) replacement therapy.

Objective: In subclinical hypothyroidism (SH), impaired diastolic function has been documented at rest and on effort, while systolic dysfunction has only been assessed on effort. Design: The aim of the present study was: (a) to further assess systolic function at rest in SH; and (b) to ascertain whether cardiac dysfunction could precede TSH increase in euthyroid patients with a high risk of developing SH. Methods: We studied 32 patients with classical Hashimoto’s thyroiditis (22 with increased serum TSH (> 3 mU/ml – group A), and 10 with normal serum TSH (< 3 mU/ml – group B)); a third group (C), which included 13 healthy controls. All subjects underwent pulsed wave tissue Doppler imaging (PWTDI) to accurately quantify the global and regional left ventricular function. Results: When compared with group C, PWTDI indices showed that in both groups A and B there was a significant impairment of systolic ejection (P < 0.001 and P < 0.05, respectively), a delay in diastolic relaxation (P < 0.001 and P < 0.05, respectively) and a decrease in the compliance to the ventricular filling (P < 0.05). Several significant correlations were found between PWTDI parameters and serum-free T3 and T4 and TSH concentrations. Conclusion: PWTDI is a sensitive technique that allows detection of both diastolic and systolic abnormalities, not only in patients with SH, but also in euthyroid subjects with a high risk of developing thyroid failure. Futhermore, the significant correlations of several PWTDI indices with serum FT3 and TSH concentrations strongly support the concept of a continuum spectrum of a slight thyroid failure in autoimmune thyroiditis extending to subjects with serum TSH still within the normal range.

AIMS Cardiac resynchronization therapy (CRT) is a well established therapy in heart failure patients who are on optimal medical therapy and have reduced left ventricular ejection fraction (LVEF) and wide QRS complexes. Although women and patients with nonischemic cardiomyopathy are under-represented in CRT trials and registries, there is evidence that these two groups of patients can benefit more from CRT. The aim of our analysis was to investigate the impact of female sex on mortality in a population that included a high percentage of patients (61%) with nonischemic cardiomyopathy. METHODS We analyzed data on 507 consecutive patients (20% women) who received CRT at two Italian Heart Transplant centers and were followed up for a maximum of 48 months. RESULTS After multivariate adjustment, women showed a trend toward better survival with regard to all-cause mortality [hazard ratio (HR) 0.32, confidence interval (CI) 0.10-1.04; P = 0.059]. However, this benefit was limited to nonischemic patients with regard to all-cause mortality (HR 0.20, CI 0.05-0.87, P = 0.032) and cardiovascular mortality (HR 0.14, CI 0.02-1.05, P = 0.056). CONCLUSION Female CRT recipients, at mid-term, have a favorable prognosis than male patients and this benefit appears to be more evident in nonischemic patients. Thus, we strongly believe that the apparent under-utilization of CRT in females is an anomaly that should be corrected.

Aims To assess the diagnostic yield of new external loop recorders (ELRs) in patients with history of syncope, pre-syncope, and sustained palpitations. Methods and results Since 2005, we have established a registry including patients who consecutively received ELR monitoring for unexplained syncope or pre-syncope/palpitations. The registry included 307 patients (61% females, age 58 ± 19 years, range 8–94 years) monitored by high-capacity memory ELR of two subsequent generations: SpiderFlash-A® (SFA®, Sorin CRM), storing two-lead electrocardiogram (ECG) patient-activated recordings by loop-recording technique (191 patients, 54 patients with syncope, years 2005–09), and SpiderFlash-T® (SFT®), adding auto-trigger detection for pauses, bradycardia, and supraventricular/ventricular arrhythmias (116 patients, 38 patients with syncope, years 2009–12). All the patients previously underwent routine workup for syncope or palpitation, including one or more 24 h Holter, not conclusive for diagnosis. Mean monitoring duration was 24.1 ± 8.9 days. Among 215 patients with palpitations, a conclusive diagnosis was obtained in 184 patients (86% diagnostic yield for palpitation). Among 92 patients with syncope, a conclusive diagnosis was obtained in 16 patients (17% clinical diagnostic yield for syncope), with recording during syncope of significant arrhythmias in 9 patients, and sinus rhythm in 7 patients. Furthermore, asymptomatic arrhythmias were de novo detected in 12 patients (13%), mainly by auto-trigger detection, suggesting an arrhythmic origin of the syncope. Conclusions The diagnostic yield of ELR in patients with syncope, pre-syncope, or palpitation of unknown origin after routine workup was similar to implantable loop recorder (ILR) within the same timeframe, therefore, ELR could be considered for patients candidate for long-term ECG monitoring, stepwise before ILR.

Reverse remodeling and increased LVEF after CRT correlate with survival and heart failure hospitalizations, but their relationship with the risk of SCD is unclear. We aimed to evaluate whether exceeding a threshold value of 35% for left ventricular ejection fraction (LVEF) 1 year after cardiac resynchronization therapy (CRT) predicts survival and freedom from sudden cardiac death (SCD).330 patients who survived ≥ 6 months after CRT (males 80%, age 62 ± 11 years) were grouped according to 1-year LVEF ≤ 35% (Group 1, n=187, 57%) or35% (Group 2, n=143, 43%). According to changes vs. baseline (reduction of left end-systolic volume [LVESV] ≥ 10% or increase of LVEF%10 units), patients were also classified as echocardiographic (Echo) non-responders (Group A, n=152, 46%) or responders (Group B, n=178, 54%).At baseline, LVESV volume was larger and LVEF was lower in Group 1 vs. Group 2 (p0.001). After 1 year, echocardiographic improvement was greater in Group 2 vs. Group 1 (p0.001 for changes in both LVESV and LVEF). Over a median follow-up of 49 months, 47 patients (14%) died, 36 in Group 1 vs. 11 in Group 2 (19% vs. 8%, p=0.004). A significantly higher rate of freedom from all-cause mortality (p=0.002), cardiovascular mortality (p0.001) and SCD (p0.001) was observed in Group 2. Multivariate analysis demonstrated that only 1-year LVEF35% was associated with freedom from SCD/VF.LVEF35% after 1 year of CRT characterizes a favorable long-term outcome, with a very low risk for SCD.