ELECTROCARDIOGRAPHIC LEFT-VENTRICULAR HYPERTROPHY IN PATIENTS WITH SUSPECTED ACUTE CARDIAC ISCHEMIA - ITS INFLUENCE ON DIAGNOSIS, TRIAGE, AND SHORT-TERM PROGNOSIS - A MULTICENTER STUDY

Objective: To understand the diagnostic and short-term prognostic sign ificance of electrocardiographic left ventricular hypertrophy (ECG-LVH ) for patients who present to the emergency department with symptoms s uggesting acute cardiac ischemia, defined as new or unstable angina pe ctoris or acute myocardial infarction. Design: Subgroup analysis of a multicenter, prospective study of coronary care unit admitting practic es in the prethrombolytic era. Setting: The emergency departments of s ix New England hospitals: two urban medical school teaching hospitals, two medical school-affiliated community hospitals in smaller cities, and tow rural non-teaching hospitals. Patients: 5,768 patients present ing with symptoms suggesting possible acute cardiac ischemia, includin g 413 patients who had ECG-LVH defined by the Romhilt-Estes point scor e criteria and 5,355 patients who had other electrocardiogram (ECG) fi ndings. Main results: Only 26% of the 413 patients who had ECG-LVH wer e ultimately judged to have had acute cardiac ischemia, compared with 72% of patients who had primary ST-segment and T-wave abnormalities (p < 0.001) and 36% of those who had other ECG abnormalities (p < 0.001) . Overall, the ECG-LVH patients were one-third less likely than the pa tients who did not have ECG-LVH to have had acute cardiac ischemia, af ter controlling for other predictors of acute ischemia by logistic reg ression (relative risk = 0.66, 95% CI 0.46 to 0.94). The patients who had ECG-LVH were only one-fourth as likely to have had acute myocardia l infarctions as were the patients presenting with primary ST-segmnt a nd T-wave changes (12% vs 48%, p < 0.001). Instead, a much larger prop ortion had had congestive heart failure or hypertension. The admitting physicians had identified ECG-LVH poorly on the admitting ECGs: only 22% of those who had ECG-LVH had been correctly identified, and for mo re than 70%, the secondary ST-segment and T-wave changes of ECG-LVH ha d been read as being primary. The short-term mortality for the patient s who had ECG-LVH was 7.5%. This was intermediate between the mortalit y for patients who had primary ST-segment and T-wave abnormalities (10 .6%) and those who had other ECG abnormalities (5.1%). Mortality was n ot affected by whether the admitting physician had recognized ECG-LVH initially. Conclusion: ECG-LVH was not a benign ECG finding among the patients who had presented with symptoms suggesting an acute cardiac i schemic syndrome: short-term mortality among the patients who had ECG- LVH (7.5%) approached that for the patients who had primary ST-segment and T-wave abnormalities (10.6%, p = 0.10). However, the patients who had ECG-LVH were one-third less likely to have had any acute cardiac ischemia than were the patients who did not have ECG-LVH, after logist ic regression was used to control for other predictors of acute ischem ia. Specifically, acute myocardial infarction was only one-fourth as l ikely when LVH was present on the admitting ECG (12%) as it was when p rimary ST-segment and T-wave abnormalities were present (48%, p < 0.00 1). Instead, congestive heart failure and hypertensive heart disease w ere more common. Thus, routine use of thrombolytic therapy for patient s who have ECG-LVH does not seem warranted. ECG-LVH was poorly recogni zed (in only 22% of cases) by the physicians in the present study. Bet ter recognition of this common ECG finding may lead to more effective patient management.