LONG-TERM EVALUATION OF PATIENTS WITH APICAL HYPERTROPHIC CARDIOMYOPATHY - CORRELATION BETWEEN QUANTITATIVE ECHOCARDIOGRAPHIC ASSESSMENT OFAPICAL HYPERTROPHY AND CLINICAL ELECTROCARDIOGRAPHIC FINDINGS

Apical hypertrophic cardiomyopathy (AHCM) is characterized by primary hypertrophy localized exclusively in the apex of the left ventricle. P revious studies have indicated that AHCM results in a unique combinati on of cross-sectional echocardiographic (CSE) and ECG findings ('giant ' T wave inversion and high R wave voltage in the precordial leads). T he aims of this study were: (1) to assess the degree of AHCM in a quan titative fashion (2) to evaluate the possible relationship between api cal hypertrophy, quantitatively determined, and ECG findings in patien ts with AHCM (3) to verify the changes in echocardiographic and ECG pa rameters over time (4) to define the relationship between the severity of AHCM and the clinical course of such patients. Eleven selected pat ients with AHCM were studied for an average 6 year follow-up period; t here were seven men and four women (age from 18 to 62 years, mean 49). Apical hypertrophy was assessed quantitatively by determining the mus cle cross-sectional area in the apical region, which was considered an index of myocardial mass. From the end-diastolic apical four chamber view, endocardial and epicardial contours were digitized in order to o btain the total muscle cross-sectional area of the left ventricle. The walls of the left ventricle were then divided into three regions (bas al, intermediate, apical). The find value of each cross-sectional musc le area was obtained from the mean measurements of four independent an d blinded observers. In AHCM the apical muscle cross-sectional area (A MA) ranged from 10.3 to 17.9 cm2, mean 13.2 +/- 2.6 cm2. The compariso n between CSE and ECG findings showed that patients with giant negativ e T wave inversions (T wave > 10 mm) and high R wave voltages (R wave > 25 mm) had a more severe degree of apical hypertrophy. However, ther e was incomplete agreement between CSE and ECG findings. During follow -up, negative T wave amplitude increased from 8.5 +/- 3.4 to 11.9 +/- 3.6 mm (mean 4.2 +/- 2.7) in 10 patients (P>0.01) and there was a mild increase of precordial R wave (from 28.0 +/- 5.9 to 29.3 +/- 5.2 mm, mean 1.5 +/- 1.6) (P = ns). The AMA change over time, from 13.2 +/- 2. 6 to 13.8 +/- 2.3 was not significant. All patients were alive at the most recent evaluation, and without significant symptomatic deteriorat ion. This study demonstrates a wide spectrum in the degree of severity of apical hypertrophy among patients with AHCM. Furthermore, ECG find ings are not uniform and are not significantly related to the severity of the hypertrophy itself. Therefore, AHCM should be considered as a part of the morphological spectrum of hypertrophic cardiomyopathy rath er than a separate entity with univocal CSE and ECG findings. Follow-u p data indicate that despite ECG results worsening over time, a signif icant progression in apical left ventricular wall thickness does not o ccur. Changes in negative T wave amplitude are not related to symptoms and are not predictive of the functional severity of AHCM. Finally, t he clinical outcome of patients with AHCM seems not be dependent on th e entity of apical hypertrophy.