Dilated cardiomyopathy: Functional status, hemodynamics, arrhythmias, and prognosis

Abstract

The natural history of dilated cardiomyopathy is variable, and the prognosis difficult to predict. Several clinical and hemodynamic parameters have been proposed as prognostic indicators. Reports on the relationship between ventricular arrhythmias, degree of hemodynamic impairment, and sudden death are controversial. To define accurately the prognosis in dilated cardiomyopathy, 55 patients with this clinical syndrome underwent clinical evaluation, radionuclide ventriculography, echocardiography, 12-lead electrocardiography, and 24 hr ambulatory monitoring, and the data thus obtained were evaluated based on predictive value. Over a follow-up period of 14.1 +/- 7.9 months, 11 patients (20%) died, all suddenly. Univariate analysis revealed that patients with more severe functional impairment (P = 0.0449), lower cardiac index (P = 0.0226), lower ejection fraction (P = 0.0426), and higher pulmonary artery wedge pressure (P = 0.0314) had greater mortality risk. Age, duration of symptoms, 12-lead electrocardiographic abnormalities, and atrial arrhythmias were not predictive of higher mortality. The number of PVCs per hr, the occurrence of couplets, the degree of PVCs prematurity, and the presence, frequency, rate, and duration of ventricular tachycardia did not have prognostic significance. A stepwise discriminant analysis identified functional class, cardiac index, and presence or absence of multiform PVCs as the group of variables that together could more accurately predict outcome in our dilated cardiomyopathy patients. Using a formula derived from the results of this analysis, the outcomes of 36 of 49 patients (74%) was correctly predicted, with a specificity of 100% and a sensitivity of 70%.

Are Nonsustained Ventricular Tachycardias Predictive of Major Arrhythmias in Patients with Dilated Cardiomyopathy on Optimal Medical Treatment?

“…Another potential limitation, common to most studies evaluating spontaneous arrhythmias by 24‐hour Holter monitoring, could be the variability of NSVT at different recordings 29 . Therefore, the incidence, length, and rate of NSVT could be underestimated without multiple recordings 30 …”

Arrhythmias in Dilated Cardiomyopathy: Incidence, Clinical Significance, and Prognostic Pattern

“…10 Survival in patients with dilated cardiomyopathy has been related to clinical characteristics, hemodynamics, and ventricular function, 11 whereas the natural history as well as prognostic value of co-existing arrhythmias remain controversial. 12 Costanzo-Nordin et al 13 indicated that the natural history of dilated cardiomyopathy is variable and the prognosis difficult to predict. They proposed several clinical and hemodynamic criteria as prognostic indicators and concluded that the relationship between arrhythmias, degree of hemodynamic impairment, and sudden death is controversial.…”

Treatment of end stage dilated cardiomyopathy

“…In fact, over 70% of these patients have non-sustained ventricular tachycardia during ambulatory monitoring. 40 The arrhythmias may be inducible in the electrophysiology laboratory but a correlation between ventricular arrhythmias and sudden death in dilated cardiomyopathy has never been confirmed.4' Decompensated congestive heart failure itself is commonly associated with ventricular arrhythmias.…”