[Comparison of clinical characteristics of Chinese patients with apical hypertrophic cardiomyopathy and typical hypertrophic cardiomyopathy].

Objective: To evaluate the clinical features in Chinese patients with apical hypertrophic cardiomyopathy (AHCM) and typical hypertrophic cardiomyopathy (HCM).

Methods: This retrospective analysis included 160 patients hospitalized in Fuwai hospital. Patients were divided into three groups: apical hypertrophic cardiomyopathy (AHCM, n = 41) group, non-obstructive typical hypertrophic cardiomyopathy group [NOHCM, LVOT < 30 mm Hg (1 mm Hg = 0.133 kPa) at rest, n = 52] and obstructive typical hypertrophic cardiomyopathy (OHCM, LVOT ≥ 30 mm Hg at rest, n = 67). Clinical features, diagnosis, therapy, and plasma levels of biomarkers of these three groups were analyzed.

Results: (1) The age at disease onset was older in AHCM group than in OHCM group [(49.9 ± 13.6) years vs. (41.4 ± 14.6) years, P < 0.01]. Exertional dyspnea appeared more often in HCM patients than in AHCM patients, NT-proBNP level was significantly lower in AHCM patients than in OHCM patients (P = 0.001). Plasma CK-MB, LDH, TnI and MYO levels were similar among the three groups. (2) Thirty-three AHCM patients were first hospitalized for suspected coronary heart disease (CHD) and CHD was excluded in 18 cases (43.9%). (3) The frequency of giant negative T waves (depth ≥ 10 mm) on ECG was 43.9%, 13.5% and 4.4% (P < 0.01) in AHCM, NOHCM and OHCM respectively. Half of AHCM patients showed left ventricular high voltage on ECG. (4) Cardiac magnetic resonance imaging is superior to echocardiography on correctly diagnosing AHCM.

Conclusion: AHCM patients differ from typical OHCM patients in clinical characteristics. There were significant differences on echocardiography and electrocardiography features among three groups. Cardiac magnetic resonance imaging and giant negative T waves on ECG are helpful for the diagnosis of AHCM.