Predictors of tachycardia-induced cardiomyopathy in patients with first-time decompensation of chro-nic heart failure with reduced left ventricular ejection fraction of nonischemic etiology and persistent atrial tachyarrhythmia.

Aim    To identify possible predictors of tachycardia-induced cardiomyopathy (TICMP) in patients with newly developed decompensated chronic heart failure (CHF) of nonischemic origin with reduced left ventricular ejection fraction (LV EF) and with persistent atrial tachyarrhythmias. Material and methods    This study included 88 patients with newly developed decompensated CHF of nonischemic origin with reduced LV EF and persistent atrial tachyarrhythmias. Resting 12-lead electrocardiography (EGC) and transthoracic echocardiography (EchoCG) were performed upon admission and following the electrical impulse therapy for all patients. Also, 24-h ECG monitoring was performed to confirm sinus rhythm stability. After recovery of sinus rhythm, outpatient monitoring was performed for three months, including repeated EchoCG to evaluate the dynamics of heart chamber dimensions and LV EF. Results    The patients were divided into two groups based on the increase in LV EF: 68 responders (TICMP patients with a LV EF increase by >10%) and 20 non-responders (patients with an increase in LV EF by <10% during 3 months following the sinus rhythm recovery). According to results of the baseline EchoCG, LV EF did not significantly differ in the two subgroups (TICMP, 40±8.3 %, 18-50 % and non-responders, 38.55±7.9 %, 24-50 %); moreover, the incidence of cases with LV EF <30% did not differ either (9 patients TICMP and 2 non-responders, р=1.0). TICMP patients compared to non-responders, had significantly smaller left atrial dimensions (4.53±1.14 (2-7) cm and 5.68±1.41 (4-8) cm, р=0.034; 80.8±28.9 (27-215) ml and 117.8±41.3 (46-230) ml, р=0.03, respectively) and left ventricular end-systolic volume (ESV) (67.7±33.1 (29-140) ml and 104.5±44.7 (26-172) ml, р=0.02, respectively). The effect of major EchoCG parameters on the probability of TICMP development was assessed by one-factor and multifactor regression analyses with adjustments for age and sex. The probability of TICMP increased with the following baseline EchoCG parameters: end-diastolic volume (EDV) <174 ml [odd ratio (OR), 0.115, 95 % confidence interval (CI): 0.035-0.371], ESV <127 ml [OR, 0.034, 95 % CI: 0.007-0.181], left atrial volume <96 ml [OR, 0.08 , 95 % CI: 0.023-0.274], right ventricular dimension <4 cm [OR, 0.042 , 95 % CI: 0.005-0.389].Conclusion    Among patients with newly developed decompensation of CHF with reduced LV EF of non-ischemic origin and persistent atrial arrhythmias, TICMP was detected in 72 % of patients. The probability of TICMP did not depend on baseline EF and duration of arrhythmias, but increased with the following baseline EchoCG parameters: EDV< 174 ml, ESV< 127 ml, left atrial volume <96 ml, right ventricular dimension <4 cm. The multifactorial analysis showed that a right atrial volume <96 ml is an independent predictor for the development of TICMP.