Tachycardia-induced cardiomyopathy (TIC) is characterized by left ventricular (LV) dysfunction resulting from persistent or highly frequent tachyarrhythmias with uncontrolled heart rate. We prospectively followed and determined the clinical outcome of rhythm control in patients with cardiomyopathy considered secondary to sustained supraventricular tachyarrhythmias (SVT).
From May 2006 to January 2008, 13 patients with NHYA class III- IV Congestive heart failure (CHF) secondary to LV-dysfunction and co-existent SVT were identified. Diagnostic possibility of TIC was considered. Restoration and maintenance of sinus rhythm was given a priority. Management was individualized on underlying rhythm, including electrical cardioversion (90%) followed by anti-arrhythmics, catheter ablation (10%) and anticoagulation. In patients with borderline systolic blood pressure (SBP), priority was given to continuation of antiarrhythmic therapy over other medications. Diuretics, Beta-blockers and Angiotensin converting enzyme inhibitors were added as tolerated. Selected patients were followed in an outpatient setting where LV function was evaluated by follow up echocardiography.
Out of the 13 patients (8 men, 5 women; mean age 61.9 ± 20.2 years), 8 had atrial fibrillation (61%), 4 had atrial flutter (31%) and 1 had atrial tachycardia (8%). Mean follow up period was about 6.5 months. Mean ejection fraction (EF) documented on first visit was 27 ± 11.4 %. All patients reported significant symptomatic improvement and were in NYHA class I at the first follow up. Follow up echocardiogram on the follow up visit revealed significant improvement in LV systolic function with a mean EF 55 ± 6.27 %.
Persistent tachycardia as a cause of dilated cardiomyopathy is common but underappreciated in clinical practice. Consideration of this possibility in differential diagnosis followed by aggressive restoration and maintenance of sinus rhythm is often rewarded by complete resolution of symptoms and recovery of LV systolic function. In patients with borderline SBP, priority given to antiarrhythmic therapy over other medications was helpful.
In patients with tachycardia-induced cardiomyopathy, aggressive restoration and maintenance of sinus rhythm is shown to be rewarded with restoration of baseline myocardial functions.
Fahad Younas, No Financial Disclosure Information; No Product/Research Disclosure Information