Purpose: The aim of this study was to verify a new criterion of hypertension-related left ventricular hypertrophy (LVH) on the basis of the dipole electrocardiotopographic technique, which provides intelligible pictorial patterns and efficient quantitative parameters for recognition of pathologic states of the heart.
Methods: Standard 12-lead and vectorcardiographic measurements with the McFee-Parungao lead system were carried out for 289 echocardiographically accessed healthy subjects and hypertensive patients with LVH. The proposed parameter index of left ventricular hypertrophy for recognition of LVH is a product of the following 3 characteristics: maximum magnitude of depolarization vector, total duration of ventricular depolarization, and local spatial integral of activation duration. This parameter was compared with several other parameters commonly used for LVH diagnosis. The diagnostic efficiencies of these parameters were statistically estimated and compared using the receiver operating characteristics (ROC curves), area under the ROC curve, and partial areas under the ROC curve (pAUC). The area under the ROC curve values were compared by the standard nonparametric method, and pAUC comparison was performed by bootstrap methodology.
Results: The ROC curves display the definite advantage of the proposed criterion, especially for the specificities greater than 0.7. Statistical comparative analysis showed that the corresponding pAUC for the index of left ventricular hypertrophy is greater than for R(x) + S(z), Cornell product, and Sokolow-Lyon criteria at confidence level > or = .95.
Conclusion: The dipole electrocardiotopography-based diagnostic criterion of LVH is demonstrated to be statistically more accurate as compared to other criteria studied. The advantage of this criterion suggests that with the use of decartograms, it is possible to reveal some additional information not accessible for other diagnostic tools. Decartograms help to visualize and quantify the redistribution of activation duration over the myocardium, thus providing a valuable instrument for heuristic analysis and dynamic observation of the heart state affected by LVH.