Improved ECG detection of presence and severity of right ventricular pressure load validated with cardiac magnetic resonance imaging

Abstract

Henkens IR, Mouchaers KT, Vonk-Noordegraaf A, BoonstraA, Swenne CA, Maan AC, Man S, Twisk JW, van der Wall EE, Schalij MJ, Vliegen HW. Improved ECG detection of presence and severity of right ventricular pressure load validated with cardiac magnetic resonance imaging. The study aimed to assess whether the 12-lead ECG-derived ventricular gradient, a vectorial representation of ventricular action potential duration heterogeneity directed toward the area of shortest action potential duration, can improve ECG diagnosis of chronic right ventricular (RV) pressure load. ECGs from 72 pulmonary arterial hypertension patients recorded Ͻ30 days before onset of therapy were compared with ECGs from matched healthy control subjects (n ϭ 144). Conventional ECG criteria for increased RV pressure load were compared with the ventricular gradient. In 38 patients a cardiac magnetic resonance (CMR) study had been performed within 24 h of the ECG. By multivariable analysis, combined use of conventional ECG parameters (rsrЈ or rsRЈ in V1, R/S Ͼ 1 with R Ͼ 0.5 mV in V1, and QRS axis Ͼ90°) had a sensitivity of 89% and a specificity of 93% for presence of chronic RV pressure load. However, the ventricular gradient not only had a higher diagnostic accuracy for chronic RV pressure load by receiver operating characteristic analysis [areas under the curve (AUC) ϭ 0.993, SE 0.004 vs. AUC ϭ 0.945, SE 0.021, P Ͻ 0.05], but also discriminated between mild-to-moderate and severe RV pressure load. CMR identified an inverse relation between the ventricular gradient and RV mass, and a trend toward a similar relation with RV volume. In conclusion, chronically increased RV pressure load is electrocardiographically reflected by an altered ventricular gradient associated with RV remodeling-related changes in ventricular action potential duration heterogeneity. The use of the ventricular gradient allows ECG detection of even mildly increased RV pressure load. hypertension; pulmonary; right ventricular hypertrophy; diagnosis; ventricular gradient; electrocardiogram MODERATELY INCREASED CHRONIC right ventricular (RV) pressure load is hard to detect noninvasively because of the position and mass of the RV (7, 13, 23). Conventional 12-lead ECG parameters of increased RV pressure load lack diagnostic accuracy, precluding their use for screening purposes (3,16,26,31,34), partly because the chest electrodes predominantly overlie the left ventricle (LV) and partly because the 12-lead ECG renders 12 separate one-dimensional projections of the three-dimensional (3-D) cardiac vector in time (25), but not in the least because the RV mass is relatively low compared with the LV mass. This scalar ECG representation hampers the direct appreciation of the ECG as a recording of a 3-D process. However, a synthesized vectorcardiogram can be easily derived mathematically from the ECG, allowing the calculation of electrocardiographic 3-D parameters. One of these parameters is the ventricular gradient (VG), a 3-D measure of ventricular action potential duration (APD) heterogene...

Local Depolarization Abnormalities Are the Dominant Pathophysiologic Mechanism for Type 1 Electrocardiogram in Brugada Syndrome

“…Furthermore, instead of an increase in the ventricular gradient that would be associated with increased heterogeneity of action potential duration (20), the ventricular gradient decreased. This is consistent with the notion that the net left ventricular contribution to the QRS T integral is effectively cancelled by enhanced terminal RV conduction delay, a process previously observed in patients with pulmonary arterial hypertension (24).…”

Electrocardiographic detection of pulmonary hypertension in patients with systemic sclerosis using the ventricular gradient

“…Most importantly, heart rate increases and the magnitude and direction of ventricular de-and repolarisation forces change due to increased RV wall stress and hypertrophy [10][11][12]. Previous studies demonstrated that the electrocardiographically derived ventricular gradient (VG) can accurately detect increased pulmonary pressures when projected in the optimal direction for detection of RV pressure overload (VG-RVPO) in a heterogeneous population suspected of PH [10,12,13]. However, the value of the VG-RVPO is still unknown in patients with SSc, who are at increased risk for development of PH.…”

Arrhythmogenic substrate in hearts of rats with monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy

“…This is associated with decreased K ϩ channel activity, although studies disagree precisely which channels (26,27,32,41). Interestingly, the changes in ventricular gradient and QT interval seen in human PAH (17,19,20) are also seen in the MCT model (16,27,32). These observations would predict that the MCT model is proarrhythmic, but this has not previously been directly investigated.…”

“…In humans, pulmonary artery hypertension (PAH) is a disease that can be unstable and RV failure is a common outcome (4,13,38). The QT interval and QT dispersion of the ECG have been reported to be increased (19,20), and the shift in ECG derived ventricular gradient [reflecting action potential duration (APD) dispersion] has been related to increased RV load (17). Such changes in electrical activity have been linked to arrhythmias (1,39), and PAH is associated with arrhythmias in patients (11).…”