Premature ventricular complex morphology : a marker for left ventricular structure and function

The shape of a premature ventricular complex (PVC) might reflect the presence or absence of myocardial disease. To test this, 100 patients with a PVC on a 12-lead electrocardiogram at cardiac catheterization or nuclear angiography were classified according to PVC morphology. Group 1 (n = 50) had PVC QRS complexes with either smooth and uninterrupted contour or with narrow (less than 40 msec) notching. Group 2 (n = 50) demonstrated PVC with broad (greater than or equal to 40 msec) notching or shelves. Clinical, electrocardiographic and angiographic variables were assessed to define group differences. All patients had one or more etiological forms of heart disease none of which distinguished either group. Groups 1 and 2 differed with respect to a history of congestive heart failure (12% vs. 66%, p = 0.0004), dilated cardiomyopathy (2% vs. 38%, p = 0.0005), and the presence of mitral regurgitation (13% vs. 58%, p = 0.001), respectively. In group 1, 45 of 50 (90%) patients with a PVC had no notching. Patients in group 2 had greater PVC QRS duration as compared with patients in group 1 (181 +/- 6 vs. 134 +/- 3 msec, p = 0.0001). End-diastolic volume index (EDVI) (78 +/- 3 vs. 139 +/- 11 ml/m2, p = 0.0000) and ejection fraction (EF) (0.59 +/- 0.02 vs. 0.34 +/- 0.03, p = 0.0000) significantly discriminated between group 1 and 2, respectively.