Time course of recovery of left ventricular systolic dysfunction in patients with premature ventricular contraction-induced cardiomyopathy.

BACKGROUND: Idiopathic ventricular arrhythmias in the form of frequent, monomorphic premature ventricular contractions (PVC) can cause PVC-induced cardiomyopathy (PICMP). The aim of this study was to determine the baseline echocardiographic characteristics and the time course and degree of recovery of left ventricular (LV) systolic dysfunction in patients with PICMP. METHODS: Study population consisted of 348 consecutive patients (205F/143M, 44 ± 19 y/o) with frequent PVCs and/or ventricular tachycardia. PICMP was defined as LV ejection fraction (LVEF) of <55% in the absence of any detectable underlying heart disease and improvement of LVEF ≥ 15% following treatment of ventricular arrhythmia. Patients with PCIMP underwent transthoracic echocardiography for LV size and function at 1 week and at 1-3 to 6-12 months of follow-up. RESULTS: Twenty-four patients (8F/16M, 47 ± 18 y/o) with PICMP with complete echocardiographic data were included in the study. Average baseline LV end-diastolic diameter, LV end-systolic volume, LV mass index, and LVEF were 55.4 ± 6.8 mm, 69.6 ± 23.3 mL, 110.2 ± 28.3 g/m2, and 41 ± 8.4%, respectively. Mild-to-moderate mitral regurgitation (MR) was present in 13 (54%) patients. Early improvement (≥25% increase in LVEF at 1-week follow-up compared to baseline) was observed in 13 (54%) patients. Patients with early improvement had higher LVEF at 12 months of follow-up compared to patients without early improvement (58.8 ± 5.0% vs 52.5 ± 6.7%, P = 0.019). CONCLUSIONS: PCIMP is characterized by mild-to-moderate global LV systolic dysfunction with slightly increased LV mass and mild-to-moderate MR. Greatest improvement in LV systolic dysfunction was observed at 1-week follow-up in our study population. Early improvement in LVEF may potentially predict the complete reversibility of LV systolic dysfunction.

Chronic cough and tachycardia-induced cardiomyopathy in a patient with idiopathic frequent, monomorphic premature ventricular contractions.

A 70-year-old woman presented with a 1-year history of dry cough. Extensive work-up ruled out common causes of chronic cough. She was found to have very frequent, monomorphic premature ventricular contractions (PVCs) and mild-to-moderate left ventricular systolic dysfunction. Propafenone 450 mg/day resulted in complete resolution of her cough and disappearance of PVCs within 24 hours of initiation. One month after the initiation of propafenone therapy, left ventricular ejection fraction normalized and her chronic cough resolved completely.

Cardiac resynchronization therapy with or without anatomical reverse remodeling does not affect defibrillation threshold.

BACKGROUND: Recent clinical trials have documented beneficial reverse-remodeling effects with cardiac resynchronization therapy (CRT). The aim of this study was to investigate the effect of CRT with or without reverse anatomical remodeling of the left ventricle on defibrillation threshold (DFT) levels in a prospective and consecutive group of patients with class II-IV systolic heart failure. METHODS: Study population consisted of 29 patients (14 women and 15 men; mean age 61±11 years old). All patients underwent baseline (within 24-hours of cardiac resynchronization therapy-defibrillator [CRT-D] implantation) and 6-month follow-up DFT testing. Reverse anatomical remodeling of the left ventricle was defined as ≥15% reduction in left ventricular end-systolic volume at the end of 6 months of follow-up compared to baseline. RESULTS: Baseline, average DFT was 8.8±5.9 J. Left ventricular end-diastolic volume was the only predictor of baseline DFT level (P=0.02) among the baseline demographics. Safety margin of at least 10 J was achieved in all patients. Average DFT at the end of 6 months of biventricular pacing was 9.2±6.9 J. One patient (3.4%) failed to have a safety margin of 10 J. Reverse anatomical remodeling was observed in 14 (48%) patients and did not have any effect on DFT level. There were no complications related to DFT testings. CONCLUSIONS: Baseline average DFT in patients undergoing CRT-D was ≤10 J in our study. CRT-D with or without anatomical reverse remodeling does not affect DFT at the end of 6 months of follow-up. High DFT level at the end of 6 months of follow-up is rare (3.4%) among patients with current CRT-D devices.

Late gadolinium enhancement CMR in patients with tachycardia-induced cardiomyopathy caused by idiopathic ventricular arrhythmias.

BACKGROUND: Idiopathic ventricular arrhythmias in the form of monomorphic premature ventricular contractions (PVC) and/or ventricular tachycardia (VT) can cause tachycardia-induced cardiomyopathy (TICMP). The aim of this study was to determine the prevalence of late gadolinium enhancement (LGE) in patients with TICMP caused by idiopathic ventricular arrhythmias. METHODS: The study population consisted of 298 consecutive patients (174 F/124 M; mean age 45±17 years) with frequent PVCs and/or VT. TICMP was defined as left ventricular ejection fraction (LVEF) of ≤50% in the absence of any detectable underlying heart disease and improvement of LVEF≥15% after effective treatment of index ventricular arrhythmia. RESULTS: Twenty-seven (9.1%) patients found to have LVEF≤50% and diagnosed as presumptive TICMP. Improvement in LVEF after effective treatment of index ventricular arrhythmia was observed in 22 of 27 patients (TICMP group; mean PVC burden of 30.8±9.9%). LVEF did not improve in five of 27 patients (primary cardiomyopathy group; mean PVC burden of 28.8±10.1%). LGE-cardiac magnetic resonance (CMR) imaging was performed in 19 of 22 patients with TICMP and one patient (5%) had LGE. All five patients with primary cardiomyopathy underwent LGE-CMR imaging and four patients (80%) had LGE. CONCLUSIONS: LGE is a rare finding in patients with TICMP caused by idiopathic ventricular arrhythmias. LGE-CMR can be used in the diagnostic work-up of patients with TICMP. Further prospective studies are required to determine the role of LGE-CMR in predicting the recovery of left ventricular systolic dysfunction in patients with presumptive TICMP.

Tachycardia-induced cardiomyopathy in patients with idiopathic ventricular arrhythmias: the incidence, clinical and electrophysiologic characteristics, and the predictors.

INTRODUCTION: Idiopathic ventricular arrhythmias in the form of monomorphic premature ventricular contractions (PVC) and/or ventricular tachycardia (VT) can cause tachycardia-induced cardiomyopathy (TICMP). The aim of this study was to determine the incidence, clinical and electrophysiologic characteristics, and the predictors of TICMP in patients with idiopathic ventricular arrhythmias. METHODS: Study population consisted of 249 consecutive patients (148 F/101 M, 45 ± 20 y/o) with frequent PVCs and/or VT. All patients underwent transthoracic echocardiography and 24-hour Holter monitoring. TICMP was defined as left ventricular ejection fraction (LVEF) of ≤50% in the absence of any detectable underlying heart disease and improvement of LVEF ≥15% following effective treatment of index ventricular arrhythmia. RESULTS: Seventeen (6.8%) patients had TICMP. Patients with TICMP compared to patients with preserved LVEF were more likely to be male (65% vs 39%, P = 0.043) and asymptomatic (29% vs 9%, P = 0.018), and were more likely to have higher PVC burden (29.4 ± 9.2 vs 8.1 ± 7.4, P < 0.001), persistence of PVCs throughout the day (65% vs 22%, P = 0.001), and repetitive monomorphic VT (24% vs 0.9%, P < 0.001). PVC burden of 16% by ROC curve analysis best separated the patients with TICMP compared to patients with preserved LVEF (sensitivity 100%, specificity 87%, area under curve 0.96). CONCLUSIONS: TICMP was relatively common (∼1 in every 15 patients) in our study population. The predictors of TICMP were male gender, absence of symptoms, PVC burden of ≥16%, persistence of PVCs throughout the day, and the presence of repetitive monomorphic VT.