The importance of clinical subsets in interpreting maximal treadmill exercise test results: the role of multiple-lead ECG systems.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to P Wagniart.
Explore the source record for details and available documents.
This coronary spasm provocation test with methyl-ergometrine maleate was carried out during coronary arteriography in 47 patients presenting with spontaneous chest pain. Coronary spasm was triggered in 16 cases, reproducing the chest pain in 11 patients, and accompanied by electrical changes in 15 cases, 12 subepicardial ischaemias and 3 subendocardial ischaemias. This test is not without danger to the patient as arrhythmias and conduction defects were recorded in 6 cases although the spasm was readily reversible on injection of intravenous glyceryl trinitrate. Of 7 patients with Prinzmetal variant angina, the test was positive 6 times, in three of which on pre existing severe organic lesions, so confirming the mechanism of this syndrome and the reliability of the test. Of 40 patients presenting with spontaneous chest pain, 10 had a positive test. In 2 of these cases the chest pain was subsequently observed with subepicardial ischaemic electrical changes, so confirming the screening value of this test. In the 7 cases where coronary spasm gave rise to electrical changes with or without pain, the logical diagnosis would appear to be spastic angina. In the 30 cases where the test was negative the subsequent outcome did not provide any proof in favour of a coronary origin of the chest pain.
Explore the source record for details and available documents.
One hundred consecutive men with a normal ECG at rest had a maximal treadmill test using 14 leads during and post-exercise. Coronary arteriography performed the following day revealed coronary stenoses greater than or equal to 70% in 66 patients. Test results obtained from a V5 lead were compared to different lead combinations and were correlated with arteriographic findings. A positive exercise test occurred in 37 men using an isolated V5 lead compared to 50 men (P less than 0.05) using 11 leads, 52 men (P less than 0.05) using a combined CM5, CC5, Cl (inferior) lead system and 58 (P less than 0.001) men using all 14 leads. The predictive value of a positive test varied between 89-95% and was not changed significantly by the addition of multiple leads. The 14 lead ECG was positive in 43/45 (96%) patients with multivessel disease. Parameters which helped to predict multivessel disease using 14 leads were 1) the time that ischemia first appeared 2) the pressure-rate product at the time ischemia first appeared, and 3) the maximum workload that could be attained. In general, the magnitude of ST-segment depression and the time required for a positive ECG to return to normal postexercise were not useful predictors of multivessel disease. We conclude that the use of multiple leads improves the sensitivity and efficiency of the maximal treadmill exercise test. The usefulness of exercise test results can be further improved if multiple leads are combined with physiologic data collected during exercise.
The exercice electrocardiogram, carried out in 160 normal subjects, has allowed us to witness the physiological mechanisms of adaptation to exercise as a function of age and sex. The relationship between systolic arterial pressure (SAP) and cardiac rate (CR) is very narrow (R = 0.97), and is a linear function. Its slope increases with age in both sexes, and differs significantly in the male and female (P less than 0.001). Systolic pressure is related to the relative cardiac rate (CR%) by the formula SAP = 1.55.CR% + 70.
A prospective study into the aetiology of presumed primary non-obstructive cardiomyopathy was carried out in 57 patients who had no lesions of the trunk of the coronary artery; one case of haemochromatosis and one of amyloidosis were found. Excluding these two cases of cardiomyopathy which were in fact secondary, most of the others were associated with manifestations or with complications of myocardial diseases (two pulmonary emboli and one case of jaundice) or pathology associated with it. Investigation into possible infection, biochemical abnormalities and dietary indiscretion (alcohol, colza oil), were unfruitful. Electromyographic changes of the "myositic" type were very common. The bicycle ergometry test was often interrupted through fatiguing of the peripheral muscles. These findings suggest that the muscular abnormalities may not be limited to the heart. The cost of an enquiry of this type has been investigated.
The 100 patients who underwent an exercise test and a follow-up coronary arteriogram at a mean interval of 10.1 months after an aorto-coronary bypass had suffered preoperatively from incapacitating angina 50%), a threatened infarction syndrome (35%), or Prinzmetal's angina (15%). The majority had a single bypass graft (72%), but 28% had two or three grafts. The exercise test was positive 39 times, negative 51 times, and indeterminate in 10. Correlation with the clinical picture shows that 27% of the patients in functional category I had a positive exercise test. Correlation with coronary arteriography shows that a positive test is reliable evidence for a defect or occlusion of the graft. On the other hand, a negative exercise test is a less reliable indicator of a good result. No instances of positive exercise tests were found when there was complete alleviation of the coronary condition.