Search

The diagnostic accuracy of the dipyridamole test in provoking coronary insufficiency was investigated in 79 patients with chest pain and the results were compared with the findings on angiography and exercise electrocardiogram. 58 patients had documented severe coronary artery stenosis, 21 had patent coronary vessels (cardiomyopathy 8, aortic stenosis 1, ectopic origin of coronary artery 1, normal 11). Anginal pain after dipyridamole was a non-specific finding. Approximately half the subjects in whom coronary insufficiency would be expected according to the coronary angiographic and ventriculographic findings evidenced ischaemic ST-segment depression after dipyridamole, which was comparable to the number of positive exercise electrocardiograms. In 23 patients, most of whom had shown an inadequate frequency response during the initial exercise test, ergometry was repeated after the administration of dipyridamole. This resulted in an increase in ischaemic ECG response from 26 to 70%. It is concluded that a stress test combining dipyridamole and submaximum exercise increases the incidence of ischaemic ST-segment depression in comparison with ergometry alone. Anginal pain without ST-segment depression proved to be without diagnostic value.

The principle of the ultrasound examination of the heart is explained and the possible applications of this method are discussed. Three case histories are presented to exemplify the usefulness of echocardiography in clinical cardiology.

Doppler-echocardiography is the most important non invasive method for the assessment of the severity of aortic stenosis. After measuring the maximal transstenotic flow velocity (= Vmax) the maximal pressure drop between left ventricle and aorta (= maximal instantaneous gradient) can bei calculated according to a simple formula. The accurate determination of Vmax may be difficult and time consuming, however, and when interpreting the Doppler-data it is important to realize that there is always a systematic numerical difference between the instantaneous gradient and those gradients which one usually measures at catheterization (peak to peak and mean gradient respectively). In mixed aortic valve disease the aortic insufficiency will distort the relationship between the various gradients still further. Despite these problems Doppler-echocardiography is extraordinarily useful in quantitating aortic stenosis and obviates the need for catheterization in most patients.

Indications, results, and complications in 400 transfemoral selective coronary arteriograms are reported. After the first 100 examinations a sharp decline in serious complications and an increase in complete studies with opacifications of both coronary arteries and left ventricle was achieved. This was thought to be due not only to mounting experience but also to total body heparinization and transfemoral use of Sones catheters with torque control. According to our results transfemoral selective coronary arteriography is considered to be an indispensable examination which may be performed by experienced investigators without hesitation when indicated.

Peripheral M-mode contrast echocardiograms at rest and during the Valsalva manoeuvre were performed in 9 patients with haemodynamically insignificant interatrial communications. Contrast echoes appeared in the left heart in all 4 patients with elevated right ventricular pressure, but also in 3 out of the 5 patients with normal right-side pressures. Thus, a positive contrast echocardiogram, while definitely proving the presence of an intracardiac communication, does not necessarily mean that the defect is haemodynamically significant. The ability to detect a patent foramen ovale non-invasively by contrast echocardiography may be useful in patients with suspected paradoxical embolism.

46 patients with coronary artery disease (at least 70% stenoses) were studied with thallium-201 imaging following dipyridamole (0.50 mg/kg bodyweight intravenously) with 4-hour control and by radionuclide ventriculography at rest and during symptom-limited bicycle exercise in supine position. 38 patients (83%) had positive thallium-201 findings with persistent defects in 18 and transient defects in 20 cases. Mean left ventricular ejection fraction (EF) fell during exercise from 56.1% +/- 13.3 to 50.2% +/- 14.5 (p less than 0.001). 43 patients (93%) showed an abnormal EF response to exercise (rise of less than 10% of the control EF during exercise). In 8 patients with false negative thallium-findings the EF did not change from rest to exercise (64.1% +/- 10.0 vs. 64.6% +/- 8.5), however, in the 20 patients with transient Tl-201 defects a significant fall of the EF was noted (60.8% +/- 9.1 vs. 49.8% +/- 10.9, p less than 0.001), in the 18 patients with persistent defects only a slight decrease of the EF was induced with exercise (47.3% +/- 14.0 vs. 44.2% +/- 16.1, p less than 0.02). Thus transient Tl-201 defects usually predict functional impairment of the left ventricle with exercise, persistent defects suggest impaired rest function with only minor further dysfunction during exercise. Compared with rest and exercise ECG in these patients, both radionuclide techniques showed a significantly higher sensitivity.

The value and limitations of phonocardiography, systolic time intervals, apex cardiography and kinetocardiography in the diagnosis of impaired cardiac function during rest and haemodynamic stress were critically reviewed on the basis of studies carried out in our laboratory, as well as reports in the literature. When compared with invasively-obtained measurements, none of the above-mentioned techniques allows the prediction of heart function quantitatively in a single given patient. However, when one considers the broad overlap of mechanocardiographic measurements in normal subjects and patients with heart disease and defines an abnormal mechanocardiogram accordingly, these methods may be used to diagnose abnormal cardiac function with adequate specificity though low sensitivity.

A brief survey is given of some of the most frequent extracardiac causes which may provoke disturbances of rhythm. The importance of psychogenic and metabolic factors is emphasized. Additional organic lesions cannot be excluded in every case.