The significance of the morphology of ventricular premature complex(VPC) as a marker for left ventricular structure and function

ABSTRACT

BACKGROUND: There has been reports which suggest that the morphologic feature of ventricular premature complex(VPC) might reflect the cardiac state. METHODS: To test this, we studied retrospectively the association between the morphologic feature of VPC(shape and duration) and cardiac state(structural and functional) by analysing the records of ECG(179 cases) obtained from reviewing echocardiogram performed in our hospital from 1988 to early 1991. Group 1(n=84) had VPC-QRS complexes with either smooth and uniterruped contour or narrow( or =0.04 sec) notching or shelves. Without taking into account of either the presence of the type of the underlying cardiac disease and other constitutional disease state, we classified the type of VPC on ECG according to the above criteria and analysed its simple association with cardiac size and functional state on echocardiogram. RESULTS: In group 1, 68 of 84 cases with a VPC had no notching. In group 2, the VPC-QRS duration was greater than group 1(0.154+/-0.022 vs 0.141+/-0.011 sec(mean+/-S.D.), p=0.0001).Left ventricular end-diastolic diameter(LVED) and ejection fraction(EF) showed a significant difference between the two groups(5.12+/-0.64 vs 5.72+/-0.95cm, p=0.0003 and 65.89+/-10.84 vs 60.82+/-15.5%, p=0.012 respectively). In group 2, 50 of 95 cases(53%) showed ejection fraction less than 64%. By defining left ventricular structural dilatation and functional impairment on echocardiogram as LEVD greater than 5.5cm and EF less than 64% respectively, the sensitivity and specificity of VPC morphology was 60% and 74% respectively. CONCLUSIONS: We conclude that a broadly(> or =0.04 sec) notched VPC of long duration(> or =0.15 sec) is a simple and reliable 12-lead ECG marker for an abnormal structural and functional state of the heart(dilatation and hypokinetic left ventricle), irrespective to underlying cardiac disease, while a VPC with smooth contour or narrow(<0.04 sec) notching with short duration(<0.15 sec) reflects a normal sized heart with normal systolic function.