Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy

Abstract

BackgroundThe electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration.MethodsWe reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups.ResultsThere was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy.ConclusionThe presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.

Electrocardiographic changes in Emphysema

“…Conversely, some patients with hypertension and LVH may have leftward P axes in the setting of emphysema[ 2 , 12 ]. Although it could be inferred that LVH may reduce the sensitivity of vertical P axis when used for detection of emphysema, this was refuted in a recent retrospective study[ 17 ]. It did not find any statistically significant difference in the mean P vector between emphysema patients with and without echocardiographic evidence of LVH, and concluded that the presence of LVH may not significantly alter the sensitivity of P wave verticalization when used as a sole criterion for the diagnosis of emphysema.…”

“…This mechanism has been substantiated by scientific data. “P-pulmonale” is much more common in obstructive lung disease and in fact, it has not been noted at all in cases of restrictive lung disease in some studies[ 17 ]. A study of patients with chronic lung disease[ 18 ] and P-pulmonale on ECGs who underwent right heart catheterization showed no significant increase in right atrial or pulmonary artery pressures among these patients.…”