CURRICULUM IN CARDIOLOGY Left ventricular hypertrophy: Diagnosis, prognosis, and management Anthony C. Pearson, MD,” Tomasz Pasierski, MD,” and Arthur J. Labovitz, MDb Columbus, Ohio and St. Louis, MO. The heart responds in well-defined ways to abnormal loads that are placed on it. The result of this response, cardiac hypertrophy, has been extensively studied in the last decade, and echocardiography has played an increasingly important role. The presence of cardiac hypertrophy is a useful marker of the car- diac response to abnormal load, which has prognos- tic implications. The purpose of this review is to summarize the clinically relevant advances that have been made in the diagnosis of left ventricular hyper- trophy and to relate these to the patient’s prognosis and management. Histologically, cardiac hypertrophy is defined as an increase in the volume of the cardiac my0cytes.l Postnatal heart enlargement is produced largely by increased size of striated muscle and hyperplasia of interstitial cells. At autopsy, left ventricular hyper- trophy is typically defined as an increase in the ab- solute mass of the left ventricle to greater than 200 gm.2 Measurement of left ventricular mass is done after removal of the atria along the plane of the atri- oventricular groove, the great vessels just under the aortic and pulmonic valves, and the free wall of the right ventricle in a plane that follows the curve on the interventricular septum.3 Hypertrophy of the ventricles represents remodel- ing of the heart architecture to normalize wall stress. The particular pattern of hypertrophy is dependent on the type of load that is imposed on the heart4 (Fig. 1). Increased afterload leads to an increase in systolic stress and the addition of sarcomeres in parallel. This results in increased wall thickness with normal or From BDepartment of Internal Medicine, Division of Cardiology, Ohio State University Hospital, Columbus, Ohio and bDepartment of Internal Medi- cine, Division of Cardiology, St. Louis University School of Medicine, St. Louis, MO. Received for publication May 29, 1990, accepted July 16, 1990. Reprint requests: Anthony C. Pearson, MD, The Ohio State University Hospital, 6th Floor Means Hall, 1654 Upham Dr., Columbus, OH 43210. 4/l/26102 decreased chamber size, and thus in an increased rel- ative wall thickness. This pattern has been termed “concentric hypertrophy” and is found in patients with pressure overload states such as systemic hy- pertension and aortic stenosis.4T 5 Increased preload leads to an increase in diastolic stress and the addi- tion of sarcomeres in series, with a resultant increase in chamber size. This type of ventricular hypertrophy with an increase in the ratio of chamber size to wall thickness has been termed eccentric hypertrophy and is common in the volume overload states of aor- tic insufficiency and mitral regurgitation.4v 5 It is im- portant to note that in eccentric hypertrophy the wall thickness remains symmetric. Eccentric hyper- trophy is usually present in the end stages of any di- lated cardiomyopathy when the ventricular dilata- tion is not balanced by an increase in wall thickness. Echocardiography allows the clear distinction be- tween concentric left ventricular hypertrophy and eccentric left ventricular hypertrophy (Fig. 2). CONSEQUENCES OF LEFT VENTRICULAR HYPERTROPHY Increased stress on the heart occurs with normal exercise. Runners or swimmers who engage in pre- dominantly isotonic exercise place a volume load on the heart, and eccentric hypertrophy develops,6, 7 whereas in weight lifters who engage in isometric ex- ercise combined hypertrophy develops.8 These “physiologic” types of hypertrophy, however, are not associated with any known adverse consequences, and both systolic and diastolic functions of the left ventricle remain normal.8-10 In addition, even normal levels of physical activity result in increased left ventricular mass. Washburn et a1.l’ studied 50 men with spinal cord injuries and 166 healthy, active men by M-mode echocardiography. Multivariate analysis revealed that physical activity was a significant independent predictor of left ven- tricular mass index after the influence of age and blood pressure had been excluded in both groups. 148