Objective: To study the clinical features, biochemical profiles, echocardiographic and electrocardiographic findings in the elderly and younger with idiopathic dilated cardiomyopathy (IDCM).
Methods: We measured biochemical profiles and reviewed the clinical features, echocardiographic and electrocardiographic findings in 40 elderly (group A) and 70 younger (group B) patients with IDCM.
Results: The aldosterone level in group A was higher than in group B (304.8 +/- 69.1 vs. 213.3 +/- 54.5 pmol/l, P < 0.05). Triiodothyronine (T3) and free T3 in group A were lower than in group B (0.78 +/- 0.21 and 2.87 +/- 0.73 vs. 1.26 +/- 0.33 nmol/l and 3.55 +/- 0.64 pmol/l, all P < 0.05). The incidence of ventricular arrhythmia in group A was lower than in group B (61.3% vs. 92.1 %, P < 0.01). The incidence of hypokalaemia and hypomagnesaemia were higher in group A (51.3% and 27.5%). 28.8% patients in group A were susceptible to digitalis intoxication. Disease duration and mean survival period in group A were longer than in group B (11.0 +/- 4.7 and 6.9 +/- 4.2 vs. 5.2 +/- 2.5 y and 3.4 +/- 2.7 y, all P < 0.05). The main cause of death in group A was congestive heart failure (78.9%) and ventricular arrhythmia (61.9%) in group B.
Conclusions: The prognosis in group A was better than in group B. The patients in group A usually showed low T3 syndrome. Ventricular arrhythmia in group A may be due to heart failure, electrolyte imbalance and sympathetic activation.