Electrocardiographic diagnosis of left ventricular hypertrophy: the effect of left ventricular wall thickness, size, and mass on the specific criteria for left ventricular hypertrophy.

BACKGROUND: The purpose of our study was to determine the relative importance and effect of an increased left ventricle wall thickness, left ventricular diastolic diameter, and left ventricular mass (LVM) on the performance of the 4 major electrocardiogram (ECG) criteria of left ventricular hypertrophy (LVH) and to determine how these findings could be incorporated into the routine ECG interpretation of LVH. METHODS: The ECG criteria of LVH that we chose to examine were voltage, repolarization abnormalities, left atrial abnormality, and ventricular conduction time. We analyzed data from 608 consecutive patients with left ventricular wall thickness of >13 mm on the echocardiogram and with a concurrent ECG. We arbitrarily divided patients into 3 groups (groups I-III) according to the calculated LVM. Group I had an LVM of <400 g; group II had an LVM from 400 to 600 g, and group III had an LVM of >600 g. We evaluated the effect of increasing LVM, wall thickness, and ventricular diameter on the performance of the 4 ECG criteria at different severity of thickness, diameter, and mass. RESULTS: An increase in the echocardiogram-derived LVM had significant effect on all 4 ECG criteria. As LVM progressively increased from groups I to III, the frequency of voltage criteria for LVH increased from 52% to 83%; left atrial abnormality rose from 46% to 68%; ST-T wave changes increases from 55% to 95%, and QRS prolongation significantly increased from 42% to 70%. CONCLUSION: Increased wall thickness and ventricular diameter failed to correlate with the overall ECG score or significantly influence the frequency of any of the 4 ECG criteria for LVH in patients when LVM was held relatively constant. We also demonstrated that an increasing number of criteria on the ECG are associated with a greater mean LVM.

Severe reversible left ventricular systolic and diastolic dysfunction due to accidental iatrogenic epinephrine overdose.

Catecholamine-induced cardiomyopathy due to chronic excess of endogenous catecholamines has been recognized for decades as a clinical phenomenon. In contrast, reports of myocardial dysfunction due to acute iatrogenic overdose are rare. A 35-year-old woman whose cervix uteri was inadvertently injected with 8 mg of epinephrine developed myocardial stunning that was characterized by severe hemodynamic compromise, profound, albeit transient, left ventricular systolic and diastolic dysfunction, and only modestly elevated biochemical markers of myocardial necrosis. Our case illustrates the serious consequences of medical errors that can be avoided through improved medication labeling and staff supervision.

Echocardiographic assessment of left and right heart hemodynamics in a patient with Lutembacher's syndrome.

We present a case of a 53-year-old woman with intractable shortness of breath that was originally ascribed to bronchiolitis obliterans organizing pneumonia. Subsequently evaluation by echocardiography and cardiac catheterization revealed that she had Lutembacher's syndrome, an uncommon combination of congenital atrial septal defect (ASD) and acquired mitral stenosis that is difficult to diagnose clinically. Our case illustrates the pitfalls and advantages of echocardiographic assessment of the mitral valve area (MVA) and the left atrial pressure (LAP). The pressure half-time method used most commonly for estimating MVA echocardiographically is inaccurate and may lead to underestimation of the severity of mitral stenosis in patients with Lutembacher's syndrome. On the other hand, the presence of ASD provides an additional method of calculating LAP, the most important determinant of symptoms in patients with mitral stenosis.