Phenotypic spectrum and clinical characteristics of apical hypertrophic cardiomyopathy: multicenter echo-Doppler study.
OBJECTIVE
The aim of this study was to define the phenotypic spectrum of apical hypertrophic cardiomyopathy (ApHCM) and clinical characteristics pertaining to identified subtypes.


METHODS
In 182 consecutive ApHCM patients (58.9 +/- 11.2 years; 142 men) with left ventricular ejection fraction > or =50%, we measured end-diastolic wall thickness of all 16 left ventricular segments to determine patterns of hypertrophy. Echo-Doppler parameters, electrocardiography patterns, and clinical findings were analyzed.


RESULTS
ApHCM was classified into three types as pure focal (n = 81), pure diffuse (n = 70) and mixed type (n = 31) according to patterns of hypertrophy. Incidence of atrial fibrillation (5% for pure focal vs. 11% for pure diffuse vs. 23% for mixed type, p < 0.05) and left atrial volume index (30.9 +/- 11.8, 35.7 +/- 14.8, and 41.3 +/- 15.9 ml/m(2), respectively, p < 0.001) were significantly different among subtypes. Peak systolic (6.6 +/- 1.0 vs. 6.3 +/- 1.2 vs. 5.9 +/- 1.1 cm/s, respectively, p < 0.05), diastolic (5.1 +/- 1.8 vs. 5.0 +/- 1.2 vs. 4.1 +/- 1.3 cm/s, respectively, p < 0.05) mitral annular velocity, E/E' (13.3 +/- 4.2 vs. 13.7 +/- 5.4 vs. 16.1 +/- 6.1, respectively, p < 0.05) were also significantly different.


CONCLUSIONS
ApHCM contains three morphologically distinct phenotypes and detailed subtyping is important in the prediction of development of atrial fibrillation, left atrial volume index and left ventricular longitudinal function.
Choi
Eui-Young
EY
Yonsei University College of Medicine, Seoul, Republic of Korea.
Rim
Se-Joong
SJ
Ha
Jong-Won
JW
Kim
Yong-Jin
YJ
Lee
Sang-Chol
SC
Kang
Duk-Hyun
DH
Park
Seung Woo
SW
Song
Jae-Kwan
JK
Sohn
Dae-Won
DW
Chung
Namsik
N
D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000503:physiopathology; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D013318:Stroke Volume