Prevalence of left ventricular hypertrophy by Echocardiography and utility of ECG voltage criteria for left ventricular hypertrophy among Ambulatory Hypertensive Patients at Mbagathi Hospital

Abstract

Left ventricular hypertrophy (LVH) is structural change and a physiological adaptation due to increased workload on the left ventricular myocardium. It is often a complication of hypertension and an independent risk factor for cardiovascular events. Echocardiography is the gold standard for assessment of LVH, however, in low resource setting it is not readily available and ECG can supplement the echocardiography in such setting. AHA/ACCF/HRS Recommendations for the standardization and interpretation of the electrocardiogram recommends testing of the available ECG criteria to identify criteria with high diagnostic yield. Objective: To determine the prevalence of LVH by echocardiography and utility of the commonly used ECG criteria for LVH using echocardiography as the gold standard among ambulatory hypertensive participants at the medical outpatient clinic Mbagathi hospital Methods: It was a cross sectional hospital outpatient based study done at Mbagathi hospital year 2016/2017. Participants with file diagnosis of hypertension were subjected to echocardiography and electrocardiography to asses left ventricular hypertrophy. Results: A hundred and four (104) hypertensive patients with a mean age of 54.7 years were studied. Majority (72.1%) were females. The prevalence of echocardiography determined LVH was 61.5%. Majority of the patients had severe LVH at 48.4%. Cornell’s voltage criterion had the highest sensitivity at 46.9% and specificity of 72.5% followed by Sokow-Lyon criterion with a sensitivity of 18.8% and specificity of 87.5%. Gubner-Ungerleider voltage criterion had the lowest sensitivity of 9.4% and specificity of 100%. R wave in AVL criterion had sensitivity of 12.5% and specificity of100%. Combination of ECG criteria improved sensitivity. A combination of all the four ECG criteria or Combination of the two most sensitive criteria demonstrated similar sensitivity and specificity at 53.1% and 67.5% respectively. Low specificity of 40% in male was observed with the Cornell’s voltage criterion and a very low specificity in males at 30% was observed with combination of ECG criteria. Receiver operator curve demonstrated largest area under the curve for combination of ECG criteria at 0.603. Conclusion – The prevalence of echocardiography determined LVH in hypertensive patients was high in this population. ECG criteria for LVH had generally low sensitivity and high specificity but combination of ECG criteria improved the sensitivity for ECG determined LVH.