Echocardiographic assessment of tricuspid regurgitation during ventricular demand pacing.

Twenty patients from our pacemaker clinic population were assessed clinically and by saline contrast echocardiography (subxiphoid view) to determine the prevalence of tricuspid regurgitation (TR) and, if TR was present, its mechanism. The patients had no known TR before lead placement, a single transvenous right ventricular pacing lead present more than 6 months (mean 52, range 7 to 138), ventricular demand pacing alternating with sinus rhythm and rate programmability. Each patient was studied in sinus rhythm and during ventricular pacing. Using the criterion of inferior vena cava (IVC) contrast reflux during ventricular systole to diagnose TR, no patient had evidence of TR in sinus rhythm, consistent with clinical examination. During ventricular demand pacing, jugular venous pulse cannon A waves developed in 10 patients, and 18 patients (including these 10) had IVC contrast reflux during ventricular systole. Analysis of the timing of IVC reflux revealed its close temporal relation to the timing of atrial systole rather than a fixed timing during ventricular systole. This reflux occurred with loss of normal atrioventricular (AV) synchrony and the underlying mechanism in all cases was shown to be right atrial contraction against a closed tricuspid valve. Two patients who did not have such a pattern with pacing maintained normal AV synchrony. These observations indicate that: TR is an uncommon accompaniment of ventricular demand pacing; the jugular venous pulse and IVC echocardiographic contrast patterns during ventricular demand pacing simulate TR when AV asynchrony [corrected] occurs; and the IVC contrast pattern of pacing induced AV asynchrony [corrected] is best termed the cannon A wave synchronous pattern.

Hemodynamics at rest and during supine and sitting bicycle exercise in patients with coronary artery disease.

To access left ventricular function and compare pulmonary capillary wedge pressure and left ventricular end-diastolic pressure in the supine and sitting positions, 20 men with angina pectoris secondary to coronary artery disease underwent hemodynamic studies at rest and during exercise in the two positions. At rest the values for cardiac index, stroke index, systolic ejection rate index and left ventricular stroke work index were lower in the sitting position; heart rate, left ventricular end-diastolic pressure and pulmonary capillary wedge pressure were similar in the two positions. All patients experienced angina during both exercise periods. At angina during supine exercise, stroke index, systolic ejection rate index and left ventricular stroke work index did not increase significantly from the resting values. In contrast, during sitting exercise, significant increases in these variables were observed. Comparison of data during exercise revealed higher values for heart rate, mean systemic pressure, cardiac index, systolic ejection rate index, left ventricular stroke work index and rate-pressure product and lower values for mean pulmonary capillary wedge pressure (20 +/- 3 versus 27 +/- 3 [mean +/- standard error of the mean] mm Hg, P is less than 0.001), and left ventricular end-diastolic pressure (24+/- 3 versus 31 +/- 3 mm Hg, P is less than 0.02) in the sitting position; stroke index and S-T segment depression were similar during the two exercise periods. Four patients had insignificant increases in left ventricular filling pressure during both exercise periods. Of the 16 patients with abnormal left ventricular filling pressure during supine exercise, only 10 had a similar response during exercise in the sitting position. There was a good correlation between left ventricular end-diastolic pressure and mean pulmonary capillary wedge pressure at rest and during exercise in the two postures.

Effect of nitroglycerin ointment on the clinical and hemodynamic response to exercise.

The effects of nitroglycerin ointment (15 mg nitroglycerin) on hemodynamics at rest and during exercise were studied in 12 patients with coronary artery disease and exertional angina (angina group) and in 8 patients with normal coronary arteriograms or with nonsignificant arteriographic abnormalities who did not have exertional chest pain (nonangina group). In both groups at rest nitroglycerin ointment induced within 15 minutes a significant decrease in left ventricular end-diastolic pressure that was sustained for at least 60 minutes; systemic arterial pressure also decreased within 15 minutes and continued to decrease during the 60 minutes of observation. By 30 to 60 minutes there were significant decreases in cardiac index, stroke index, left ventricular stroke work index and tension-time index. During exercise performed 60 minutes after receiving nitroglycerin ointment, 10 of the 12 patients in the angina group had no pain, whereas 2 had delayed and less severe symptoms. Hemodynamic observations during this exercise period revealed significant decreases in left ventricular end-diastolic pressure, systemic pressure and tension-time index from values in the initial exercise period; heart rate remained unchanged. These data document the protective effect of nitroglycerin ointment for a period of at least 60 minutes and also suggest that the beneficial effects are related to a reduction in myocardial oxygen requirements.

Gastroepiploic-coronary anastomosis. A viable alternative bypass graft.

Although increasing use is being made of arterial grafts (the internal mammary arteries) for direct myocardial revascularization, it is frequently not possible to reach the posterior surface of the heart with the internal mammary as either a pedicle or a free graft. Since June 1984 we have used the right gastroepiploic artery in nine patients as a pedicle graft to the distal right coronary artery (four patients), the posterior descending artery (three patients), and the distal circumflex branches (two patients). Eight patients survived the operation. Celiac axis opacification confirmed patency in six and coronary angiography strongly suggested patency in the remaining two. All survivors are functionally in New York Heart Association Class I or II. The early angiographic and clinical results demonstrate the feasibility of using the right gastroepiploic artery as a bypass graft to coronary vessels on the posterior surface of the heart when traditional conduits are unsuitable. If its long-term patency as a living arterial graft is similar to that of the internal mammary arteries, the gastroepiploic artery may become the coronary bypass graft of choice for the distal right coronary and circumflex systems.

Management of the multiproblem seductive patient.

A seductive gesture by a patient towards a physician is not uncommon in clinical practice, and presents a variety of problems in maintenance of the doctor-patient relationship and management of the patient's medical problems. Medical, psychological, and social factors must be considered in resolving these problems. This Grand Rounds presents such a case and discusses alternative approaches to patient management and the role of other health professionals in the care of such patients.

Selective coronary arteriography: arteriographic patterns in coronary heart disease.

The severity and distribution of coronary arteriographic abnormalities have been reviewed in 88 patients with clinical evidence of coronary heart disease who were studied by Sones' technique. The patients were divided into four groups: myocardial infarction without angina, myocardial infarction with angina, angina with normal resting electrocardiogram, angina with abnormal resting electrocardiogram.Arteriographic abnormalities were generally diffuse throughout the coronary circulation, and at least two vessels were involved in 84 patients. Although the frequency of lesions was similar in the four groups of patients, those with previous myocardial infarction had the highest incidence of complete obstruction. Patients with angina and a normal resting electrocardiogram showed the least severe obstructive lesions. The severity of the arteriographic abnormalities was independent of the duration of clinical symptoms, and it appears that diffuse involvement of the coronary arterial tree is usually present when symptoms develop.

Selective coronary arteriography.

The technique of selective coronary arteriography, as described originally by Sones, was employed in 255 patients. Successful catheterization of both coronary arteries was carried out in 88% of these patients, and in the last 100 examinations both coronary arteries were entered in 95 patients. Selective coronary arteriography is a useful diagnostic tool but is a potentially hazardous form of examination as we encountered four episodes of ventricular fibrillation in the present series.

Isolated anomaly of the left anterior descending coronary artery.

An isolated anomaly of the left anterior descending coronary artery arising from the right sinus of Valsalva is described. A review of the literature shows that isolated anomalies of this vessel are very rare. However, the inability to visualize this vessel from the left sinus of Valsalva warrants careful search of the right sinus.

Hemodynamic effects of pacing-induced tachycardia in valvular aortic stenosis.

The hemodynamic effects of tachycardia were studied in 13 patients with valvular aortic stenosis. Observations were made during sinus rhythm (average heart rate 80 beats/min) and two periods (P1 and P2) when atrial pacing increased the heart rate to 109 and 131 beats/min respectively. The cardiac index did not change, but the left ventricular stroke work index fell from 61.8 to 39.5 g X m/m2 (p less than 0.001) as the heart rate increased. The left ventricular end-diastolic pressure averaged 18 mm Hg during sinus rhythm and fell to about 11.5 mm Hg at P1 and P2 (p less than 0.001). The brachial arterial systolic pressure did not change during pacing, but the left ventricular systolic pressure fell from 208 mm Hg to 201 mm Hg during P1 (p less than 0.05) and 193 mm Hg during P2 (p less than 0.001). The mean systolic aortic valve gradient averaged 64 mm Hg during sinus rhythm and fell to 51 mm Hg during P2 (p less than 0.001), and the peak aortic valve gradient fell from 82 to 69 mm Hg during P2 (p less than 0.001). The left ventricular ejection time fraction increased from 26.9% during sinus rhythm to 31.9% during P1 (p less than 0.05) and 34.7% during P2 (p less than 0.005). Because of the prolonged left ventricular ejection time fraction and smaller stroke volume, a smaller pressure gradient developed across the stenosed valve at higher heart rates. The pacing test was of little value in assessing left ventricular function and thus is not useful during invasive investigations of valvular aortic stenosis.

Fate of omental graft after revascularization of the heart.

Three patients who had had epicardiectomy, and internal mammary artery and omental grafts implanted as part of myocardial revascularization, recently underwent a second operation for coronary artery bypass grafting. All internal mammary artery implants were patent and appeared to revascularize the myocardium distal to the occluded segment of the coronary artery, as determined by angiography. Although adhesions were present at operation, there was no evidence of the free omental graft in two patients. The pedicled omental graft was present and viable in the remaining patient, but did not appear to have vascular communication with the epicardiectomized myocardium.