Echocardiographic pattern of left ventricular function recovery in tachycardia-induced cardiomyopathy patients

Background Tachycardia-induced Cardiomyopathy (TIC) represents a reversible type of cardiomyopathy (CM) that is underdiagnosed. Prior pilot studies suggested a specific left ventricular (LV) function recovery pattern in TIC patients. Cardiac chamber remodeling in TIC, however, remains incompletely understood. Purpose We aimed to explore differences in LV dimensions and functional recovery in TIC patients when compared to a control group of patients with other forms of CM and functional recovery. Methods We identified patients with reduced left ventricular ejection fraction (≤50%) and/or atrial fibrillation or flutter treated between 2015 and 2022. Patients had at least two serial transthoracic echocardiographies (TTE). The minimal interval between the TTEs had to be at least 3 months, and the left ventricular ejection fraction (LVEF) had to either improve (≥15% in absolute value) or normalize (LVEF at follow-up ≥50%). Patients were then divided into two groups: A) patients with atrial fibrillation or atrial flutter at baseline and sinus rhythm at follow-up. These patients were assumed to have TIC. B) Patients with sinus rhythm at both baseline and follow-up, consisting of patients with other forms of CM. The change in ventricular dimensions and function (indexed left ventricular end-systolic – LVESDI, end-diastolic diameters – LVEDDI – and volumes – LVEDVI, LVEF, and fractional shortening – FS) were compared within and across group A and B at baseline and at follow-up. The groups were compared using Kruskal (for independent data) and Wilcoxon (for paired data) tests. A p<0.05 was considered significant. Results A total of 261 patients were included (34% female, median age 68 years). The median time between TTEs was 25 months. 104 (39.8%) patients were considered to suffer from TIC and 157 (60.2%) patients were considered to suffer from other forms of CM. The changes in ventricular dimensions and function in both groups are shown in Figure 1 and Table 1. The TIC group showed no improvement in LVEDVI from baseline to the follow-up examination, while the control group showed significant improvement in LVEDVI (1.7% [−24.7, 22.8] vs. 12.4% [−7.1, 29.3], p=0.008). There was no difference in LVEDDI recovery between TIC and control patients (1.7% [−7.3, 10.3] versus 3.1% [−5.4, 10.2], p=0.578). Conclusions TIC patients have a specific pattern of functional recovery with similar improvements in systolic function and diameters compared with patients with other CMs, while diastolic parameters remained impaired. Funding Acknowledgement Type of funding sources: None.