Article révisé par les pairs
Résumé : This study concerns the search for electrocardiographic criteria of pulmonary arterial hypertension in patients suffering from chronic bronchopulmonary disease. The material comprised 274 cases for which the results of cardiac catheterization were available. The cases presenting arterial hypertension (blood pressure above 160/100 mm Hg), congenital or valvular ischaemic heart disease, or a generalized condition likely to affect the heart were excluded from the study. After the normal limits of the parameters under study had been determined, all possible combinations were considered in order to ascertain the minimum number of criteria that would point to pulmonary hypertension (i.e. a mean pressure above or equal to 20 mm Hg). A first, and very simple, procedure consists of seeking one of the 3 following criteria: T wave negative in V1, V2 and V3; QRS axis above 90°; and the ratio 100 P/(R+S)>26. A correct diagnosis was made in 73 of the 136 patients presenting abnormal mean pulmonary arterial pressure; 8 normotensive persons were classified as abnormal (false positive results). Sensitivity was 53.6% and specificity 94.2%. The procedure requiring the presence of 2 out of 7 pathological criteria is preferable, from the point of view of both sensitivity and specificity. The 7 criteria selected were as follows: T wave negative in V1, V2 and V3; QRS axis above 90°; ratio 100 R/(R+S) in V5 below 50; amplitude of P in L2 above or equal to 2 mm; ratio 100 P/(R+S) in L2 above 20; ratio 100 R/(R+Q) in aVR above 50; and ratio 100 R/(R+S) in V1 above 50. With this procedure, 80 cases of pulmonary hypertension out of 136 could be classified correctly, with 5 false positive results. Using the same 7 criteria, if 3 of them are required in order to conclude that pulmonary hypertension is present, sensitivity is appreciably reduced: 49 cases of pulmonary hypertension out of 136 would be classified correctly. On the other hand, specificity is excellent (only 2 false positive results). These results show that, for a population study with chronic pulmonary diseases comparable to the authors' series, as soon as 2 criteria out of the 7 sought are abnormal, there is a high probability of pulmonary hypertension. When 3 of the criteria are abnormal, pulmonary hypertension almost certainly exists.