Electrocardiographic features of different hypertrophic distribution in hypertrophic cardiomyopathy

Objective The electrocardiographic features of different hypertrophic distribution were analyzed to establish the electrocardiogram diagnostic procedure of different types of hypertrophic cardiomyopathy (HCM) . Methods Sixty-nine patients with HCM were divided into four groups: GroupⅠ (only Apex) , GroupⅡ (Apex+Base) , GroupⅢ (only Base) , GroupⅣ (Base+noApex) . Electrocardiographic parameters were assessed by chi-square test. Results ①T wave inversions (100.0%, 83.3%, 35.7%, 50.0%, respectively , P<0.01) , and giant negative T wave (44.4%, 38.9%, 0, 0, respectively, P<0.05) were more common in GroupⅠ andⅡ.The T-wave inversions were commonly revealed in leadⅠ and aVL, lead V3 to V6.The giant negative T wave were commonly in lead V3 to V5.②Left ventricular high voltage (44.4%, 72.2%, 21.4%, 28.6%, respectively, P<0.05) was more common in GroupⅡ.③Non-simple apex type was prone to QRS notch (0, 38.9%, 57.1%, 39.2%, respectively, P<0.05) , and notched QRS was common in lead Ⅲ and aVF. ④Asymmetric septal hypertrophic cardiomyopathy ASH paitents had more longer QTc interval (470.9±39.9) ms. Pathologic Q waves were more common in GroupⅣ (44.4%, 27.8%, 50.0%, 35.7%, respectively, P<0.05) . ⑤Patients with interventricular septum were prone to deep and not wide pathological Q waves common in leadⅠ and aVL (30.8%) , lead Ⅲ and aVF (46.2%) , lead V5 and V6 (38.5%) .Group Ⅰ had no pathologic Q waves. Conclusion Simple T wave inversion in left thoracic leads may indicate apical hypertrophic cardiomyopathy. QRS notches with left ventricular high voltage and notched QRS indicated apical mixed hypertrophy.The prolongation of QT interval may indicate simple septal type hypertrophy, deep and narrow pathologic Q waves in left precordial leads and inferior leads may indicate other sites hypertrophy combined with interseptum hypertrophy. Key words: Electrocardiography; Cardiomyopathy, hypertrophic; Distribution of hypertrophy