Analysis of clinical characteristics and diagnosis of 163 patients with chronic Keshan disease

Abstract

Objective To observe the incidence and clinical characteristics of chronic Keshan disease in recent years, and to provide evidence for diagnosis of the disease. Methods From March to August 2009, 163 patients with chronic Keshan disease were chosen from Shandong, Sichuan, Inner Mongolia and Cansu. Of these patients, 62 cases were from Shandong, 34 cases from Sichuan, 37 cases from Inner Mongolia, and 30 cases from Gansu. All of the subjects underwent detailed natural history of the disease, careful physical examination and electrocardiogram (ECG), X-ray chest radiography and cardiac ultrasound examination. The incidence and clinical features were analyzed. Results Adults accounted for 98.8%(161/163) and children for 1.2%(2/163) in 163 cases of chronic Keshan disease, with an average age of 45.8 years. Slow onset accounted for 62.6%(102/163), other types that evolved into chronic-type accounted for 37.4%(61/163). Low blood pressure( 116.5/72.4 mmHg),often with cardiac function grade Ⅱ accounted for 65.6%(107/163). Common symptoms were: palpitation[86.5%(141/163)], asthma [76.7% (125/163)], fatigue[76.1%(124/163)], precordial discomfort [54.6% (89/163)], dizziness[50.3%(82/163)], edema of lower limbs[44.8%(73/163)], and anorexia[38.0%(62/163)]. Common signs were: low-weak first heart sound[66.9%(109/163)], heart enlargement[64.4%(105/163)], apical pulse dispersion[42.3%(69/163)], arrhythmia[40.5%(66/163)], hepatomegalia[39.3%(64/163)], systolic murmur [25.2%(41/163)], and edema[20.9%(34/163)]. Abnormal ECG detection rate was 93.9%(153/163), with common types followed by ST-T changes[ST-T changes, ST segment changes, Tchange, 36.2%(59/163)], ventricular premature [occasional and frequent ventricular premature, 26.4% (43/163)], complete right bundle branch block [25.8% (42/163)], atrial fibrillation[19.0%(31/163)], and atrioventricular conduction block[8.6%( 14/163)]. X-ray results showed that significant and moderate heart enlargement were common, accounting for 73.4%( 105/143), followed by mild enlargement of 25.2%(36/143). Color doppler ultrasound examination results showed that the atrio-ventricular cavity diameter increased, followed by left ventricular end-systolic diameter increased[81.3%(52/64)], left ventricular end-diastolic diameter increased[65.6%(42/64)], left atrial enlargement[51.6%(33/64)], right atrial enlargement [43.8%(28/64)], and right ventricular enlargement[32.8%(21/64)]. Left ventricular wall and interventricular septum thinning accounted for 15.6%( 10/64) and 7.8%(5/64), respectively. Conclusions In recent years, most cases of chronic Keshan disease occur as natural chronic type, and at older age at onset with low blood pressure.Main clinical features of the disease are cardiac enlargement, inadequate tissue perfusion, and venous stasis performance caused by cardiac decompensation. Correct diagnosis of chronic Keshan disease can be made based on these clinical features. Key words: Keshan disease; Electrocardiography; X-rays; Echocardiography