Published online Dec 31, 1994.
https://doi.org/10.4250/jkse.1994.2.2.199
Electrocardiographic Characteristics of Hypertrophic Cardiomyopathy : Echocardiographic and Electrocardiographic Study
Abstract
Background
Patients with hypertrophic cardiomyopathy(HCMP) may present a wide spectrum of electrocardiographic abnormalities. Although many ECG criteria for left ventricular hypertrophy were tried to diagnose HCMP, there is no single criterion which has acceptable sensitivity and specificity. Recently, Allen et al reported that 12 QRS summation criteria was superior to other conventional ECG criteria in HCMP. But the reported sensitivity was relatively low and further study may be warranted. This study examines the relations between the morphology of HCMP and various criteria of left ventricular hypertrophy.
Methods
1) Study population : Among 18,183 patients who underwent echocardiography from june 1990 to Octover 1993 at Yonsei Cardiovascular Center echocardiography laboratory, 63 patients who were diagnosed as HCMP by two independent echocardiographers were enrolled to study population. All patients with HCMP have at least one segment of left ventricular wall measuring 17mm or more in thickness at end diastole. Each patient had no significant valvular disease and uncontrolled hypertension. We obtained all standard 12 leads ECGs in each 63 patients which was taken within 3 months of echocardiographic examination. 2) The summation of total QRS voltage and depth of T wave inversion in all 12 leads were measured by caliper and the R wave transitional zone in precordial leads was determined by visual estimation. To compare with otehr criteria of left ventricular hypertrophy such as Ramhilt-Estes point score, Sokolow-Lyon index, and RV6 : RV5 ratio, all available data were obtained in all ECGs.
Results
1) Twelve leads QRS voltage summation criteria was the most sensitive to diagnose HCMP comparing with other criteria such as Sokolow-Lyon, RV6 : RV5, and Romhilt-Estes criteria. 2) Modified Romhilt-Estes criteria was equivalently sensitive compared with oter published results. Left atrial enlargement pattern and left axis deviation were more freqently observed in apex-sparing group than apical involved group with statistical significance. 3) The summation of depth of T wave inversion in 12 lead and transitional zone of R wave revealed statistically significant difference between apical involved and apex-sparing groups. 4) The giant T wave inversion was not observed in any patient with obstructive pattern. 5) While Sokolow-Lyon and Romhilt-Estes creteria were not affected by age, sex, and degree of obersity, twelve leads QRS voltage summation criteria and RV6 : RV5(Holt-Spodick) criteria were significantly affected by them.
Conclusion
In diagnosing HCMP using electrocardiographic data. 12 lead QRS voltage summation criteria is most sensitive. The depth of T inversion and transitional zone have statistically significant difference between apical involvement and apex sparing HCMP groups. Which may be warranted larger scale study. When diagnosing HCMP with more than moderate degree of hypertrophy, the sensitivities of Sokolow-Lyon criteria and Romhilt-Estes score index were not significantly affected by age, sex, and obesity but those of RV6 : RV5 and 12 lead QRS summation were significantly affected.
