Progression of hypertrophic cardiomyopathy into a hypokinetic left ventricle: Higher incidence in patients with midventricular obstruction

Sayid Fighali, Zvonimir Krajcer, Sidney Edelman, Robert D. Leachman
1987 Journal of the American College of Cardiology  
The development of segmental or generalized left ventricular hypokinesia is an unusual occurrence in patients with hypertrophic cardiomyopathy. To determine the incidence and possible pathophysiologic mechanisms reo sponsible for this process, the serial clinical and laboratory data of 62 patients with the diagnosis of hypertrophic cardiomyopathy were analyzed. During a mean follow-up period of 8 years (range 2 to 21), 5 patients (Group A)developed leftventricular hypokinesia, whereas the
more » ... ing 57 patients (Group B) continued to exhibit the clinical and laboratory findings of hypertrophic cardiomyopathy. Three patients developed a dilated left ventricle with generalized hypokinesia; two other patients had segmental left ventricular wall motion abnormalities. None of these five patients who developed left ventricular hypokinesiahad fixed coronary artery disease. The mean Hypertrophic cardiomyopathy has been reported to progress occasionally into a dilated hypokinetic left ventricle (1-5). This process can occur acutely or chronically and can be associated with a significant deterioration in clinical status. Although the pathophysiology of this process is not fully understood, some cases have been reported after a myocardial infarction (1,3,5) or surgical septal myotomy and myomectomy (2). In an attempt to elucidate the pathophysiologic mechanisms responsible for this process, 62 consecutive patients with hypertrophic cardiomyopathy were followed up for a mean period of 8 years (range 2 to 21) to determine the incidence and possible predictors of development of left ventricular hypokinesia. age, sex, mean duration of follow-up, presence of coronary myocardial bridges and angina pectoris, and an interventricular gradient were all similar in Groups A and B. Midventricular obliteration was seen in 4 (80%) of the 5 patients in Group A and in 4 (7%) of the 57 patients in Group B (p < 0.001). Findings from this study reveal that segmental or generalized left ventricular hypokinesia can develop in patients with hypertrophic cardiomyopathy in the absence of fixed coronary artery disease. Such hypokinesia can occur after an acute myocardial infarction or it can develop gradually without clinical or electrocardiographic evidence of infarction. Patients with the midventricular obliteration variant of hypertrophic cardiomyopathy are at a higher risk of developing segmental or diffuse left ventricular hypokinesia. (J Am Coil CardioI1987;9:288-94) Methods Study patients. The medical records of 62 patients with hypertrophic cardiomyopathy followed up by one group of cardiologists were reviewed. In some patients the diagnosis of hypertrophic cardiomyopathy was made before referral to this center. The diagnosis was suspected on the basis of clinical and electrocardiographic findings and was confirmed by the presence of typical echocardiographic or angiographic findings, or both. The echocardiographic criteria included: I) asymmetric septal hypertrophy; 2) small left ventricular cavity; 3) reduced septal systolic motion; and 4) in the presence of left interventricular obstruction, systolic anterior motion of the anterior mitral leaflet and early systolic closure of the aortic valve. The angiographic criteria included I) a hypertrophic hypercontractile left ventricle with systolic obliteration of different parts of the left ventricle. and 2) in the obstructive form, the presence of a dynamic intraventricular gradient. All patients underwent cardiac catheterization and, when
doi:10.1016/s0735-1097(87)80377-7 pmid:3805517 fatcat:wa5xouivh5cz7bhhxou4whk3e4