Use of stents to treat kinks causing obstruction in a left internal mammary artery graft.

Left internal mammary arteries (LIMA) are used routinely as grafts to the left anterior descending coronary artery (LAD) in selected patients undergoing coronary artery bypass graft (CABG) surgery because of better long-term patency rates. Pathology other than fibrointimal hyperplasia, accelerated atherosclerosis, or thrombus can sometimes cause obstructive lesions in such grafts. This report illustrates a kink in a LIMA graft to the LAD causing an obstructive lesion shortly after surgery and describes the subsequent management of this lesion with intracoronary stents.

Detachment of transluminal extraction catheter cutter head from shaft and successful retrieval.

Transluminal extraction catheter atherectomy has been shown to be a clinically effective interventional technique for the treatment of thrombotic degenerative saphenous vein bypass grafts. We will report the first case of detachment of transluminal extraction catheter cutter head from the shaft and its successful retrieval during a saphenous vein bypass graft intervention.

Ventricular systolic and diastolic impairment during pacing-induced myocardial ischemia in coronary artery disease: simultaneous hemodynamic, electrocardiographic, and radionuclide angiographic evaluation.

This study examined the impairment in systolic and diastolic performance of both ventricles during pacing-induced myocardial ischemia in 12 men with coronary artery disease. Simultaneous hemodynamic, ECG, and radionuclide angiographic assessments were made: pre pacing (pre-P); intermediate pacing (P-1); maximum pacing (P-2); and immediately after pacing (post pacing (P-P). The prepacing measurements were made with the patient in the supine position and during leg elevation. Pacing produced a leftward and upward shift in the diastolic pressure-volume relation, a progressive decrease in left ventricular (LV) end-diastolic volume (p less than 0.003) and right ventricular (RV) end-diastolic volume (p less than 0.01), concomitant with an increase in the pulmonary artery wedge pressure (p less than 0.004) and the right atrial pressure (p less than 0.04). The shift in the LV pressure-volume relation was associated with an initial increase (P-1), followed by a decrease (P-2) in the peak filling rate (p less than 0.001). Pacing also resulted in systolic dysfunction: abnormal LV ejection fraction responses in eight patients, LV regional wall motion abnormalities in eight patients, and abnormal RV ejection fraction responses in seven patients. Leg elevation resulted in a 7% increase in cardiac output, a 20% increase in RV end-diastolic volume, a 28% increase in right atrial pressure, a 29% increase in pulmonary artery wedge pressure, and a 10% increase in LV end-diastolic volume (p less than 0.05). Thus, the ischemic response to pacing results in systolic and diastolic LV and RV dysfunction, with the diastolic impairment being more frequent than the systolic impairment.

Effects of esmolol on patients with left ventricular dysfunction.

This study examined the effect of esmolol, an ultrashort-acting beta-receptor blocker, in 10 patients with severe left ventricular dysfunction. Simultaneous hemodynamic and radionuclide angiographic measurements were obtained at incremental doses of esmolol (2, 4, 8, 12 and 16 mg/min). At a dose of 4 mg/min, esmolol produced beats blockade: a decrease in heart rate from 91 +/- 4 to 83 +/- 4 beats/min (p less than 0.05) (mean +/- SEM) and a decrease in systolic aortic pressure from 133 +/- 5 to 128 +/- 5 mm Hg (p less than 0.05). At the maximal dose, the heart rate decreased to 79 +/- 3 beats/min (p less than 0.05) and biventricular function was depressed; the left ventricular ejection fraction decreased from 27 +/- 2 to 21 +/- 2% (p less than 0.05) and the right ventricular ejection fraction decreased from 38 +/- 2 to 29 +/- 2% (p less than 0.05). These changes were accompanied by increases in left ventricular end-diastolic volume (p less than 0.05), left ventricular end-systolic volume (p less than 0.05) and pulmonary artery wedge pressure (p less than 0.05), as well as a decrease in cardiac output (p less than 0.05). The hemodynamic abnormalities (which showed considerable interindividual variability) returned to near baseline levels 10 to 30 minutes after infusion was stopped. Thus, esmolol can be administered to patients with severe left ventricular dysfunction. The beneficial effect (beta-adrenergic blockade) is usually achieved with small doses without clinically important hemodynamic changes. At larger doses, however, significant changes in biventricular function may be observed.

Effect of collateral vessels on prognosis in patients with one vessel coronary artery disease.

The prognostic implications of coronary collateral channels were examined in 359 medically treated patients with one vessel coronary artery disease and a normal left ventricular ejection fraction (greater than or equal to 50%). There were 149 patients with isolated left anterior descending coronary artery disease (group I) and 210 patients with isolated left circumflex or right coronary artery disease (group II). Collateral channels were present in 68 patients (46%) in group I and 115 patients (55%) in group II. During a follow-up period of up to 82 months (mean +/- SD 34 +/- 18), there were 23 cardiac events (4 patients died of cardiac causes and 19 patients had a nonfatal acute myocardial infarction). Actuarial survival analysis showed that the risk of cardiac events was not related to the presence of collateral channels in the two groups. Thus, the risk of cardiac events is not related to the presence or absence of collateral channels in patients with one vessel coronary artery disease. Further, the risks of cardiac death (0.3%/yr) and nonfatal myocardial infarction (1.9%/yr) are very low in medically treated patients with one vessel coronary artery disease and a normal left ventricular ejection fraction.

Forward ejection fraction: a new index of left ventricular function in mitral regurgitation.

Previous studies have shown that a normal LVEF is not a reliable index of LV function in MR. We hypothesized that the forward EF, which is the forward stroke volume (measured by Fick or thermodilution) divided by end-diastolic volume (measured by contrast ventriculography) may be a useful index of LV function, since it represents LV emptying into the aorta. This index was examined in 54 patients with chronic MR who had normal EF (greater than or equal to 50%). There were significant correlations between the forward EF and the end-diastolic volume index (r = -0.69, p less than 0.001), end-systolic volume index (r = -0.64, p less than 0.001), cardiac index (r = 0.43, p less than 0.01), and the ratio of systolic pressure-to-end-systolic volume (r = 0.65, p less than 0.001). Patients were divided into two groups according to the forward EF: group I (n = 34) had forward EF less than or equal to 35%; and group II (n = 20) had forward EF greater than 35%. Of the 32 patients who subsequently underwent mitral valve replacement, 24 patients were in group I and eight patients were in group II. At a mean follow-up of 35 months, four patients died; all of them were in group I. Improvement in functional class occurred in 75% of surgical survivors (80% in group I and 63% in group II, p = NS). These preliminary data suggest that forward EF may be a useful index of LV performance in patients with MR who have normal EF.

Primary coronary artery dissection.

Three patients had angiographic appearance of chronic primary coronary artery dissection with features that differed from other patients with this entity studied at autopsy; they were men, greater than or equal to 40 years of age, had angina pectoris and severe coronary artery disease. The right coronary artery, which was the artery involved with dissection, had only mild atherosclerosis. Further studies are needed to determine the natural history of this angiographic finding.

Percutaneous left heart catheterization and coronary arteriography with and without an arterial sheath in patients without peripheral vascular disease.

The advantages and disadvantages of an arterial sheath to introduce catheters percutaneously through the femoral artery were prospectively studied in 184 consecutive patients without peripheral vascular disease undergoing routine diagnostic left heart catheterization and coronary arteriography. The arterial sheath was used randomly in 91 patients (sheath group) and the standard Seldinger technique in 93 (control group). There were no differences in age or sex between the two groups. All patients were studied with no premedication and had the same dose of lidocaine local anesthesia and heparin. No major complication occurred in any of the patients in the sheath or control groups. There were no significant differences in groin hematomas between the two groups. The patients in the control group more commonly had severe or moderately severe discomfort requiring additional local anesthesia. We conclude that the use of an arterial sheath percutaneously for introduction of catheters for left heart catheterization and coronary arteriography is advisable, particularly for anxious patients who have a low pain threshold.

Correlation between changes in R wave amplitude and left ventricular volume induced by rapid atrial pacing.

To examine the Brody effect in humans, we studied 15 patients by means of coronary sinus pacing. We measured left ventricular (LV) volumes from the cardiac output (measured by the thermodilution technique) and LV ejection fraction (measured by radionuclide ventriculography). Pulmonary blood volume was determined by means of cardiac output and mean pulmonary transit time. In six patients, pacing was performed at two different rates, resulting in 21 pacing measurements. The heart rate increased with pacing from 73 +/- 11 to 119 +/- 19 bpm (mean +/- standard deviation, p less than 0.001). The end-diastolic volume (EDV) and the end-systolic volume (ESV) decreased with pacing (p less than 0.001 each). The R wave amplitude decreased with pacing (1.44 +/- 0.63 mV control vs 1.32 +/- 0.58 mV with pacing; p less than 0.01). R wave amplitude decreased in 19 of the 21 pacing studies (90%); EDV and ESV decreased in all 21 pacing studies, and pulmonary blood volume decreased in 14 of the 15 pacing studies (93%) performed in 11 patients. There was a significant correlation between the percentage of change in R wave amplitude with the percentage of change in EDV (r = 0.54, p less than 0.01) and with the percentage of change in ESV (r = 0.54, p less than 0.01). These results, therefore, validate Brody's hypothesis and indicate that changes in LV volumes affect the R wave amplitude.

Rapid progression of coronary stenosis in patients with unstable angina pectoris selected for coronary angioplasty.

We studied the course of coronary stenosis in the first 62 patients (45 men and 17 women) referred for coronary angioplasty in the interval between the diagnostic arteriogram and the preangioplasty coronary arteriogram. In 42 patients, the stenosis was in the left anterior descending artery, in 17 patients in the right coronary artery, in one patient in the left circumflex, and in two patients in the vein graft. Twenty-six patients had stable angina pectoris, 34 patients had unstable angina, and two patients had no angina. The coronary stenosis did not change significantly in any patient with stable angina. Conversely, the stenosis progressed in nine of the 34 patients with unstable angina (26.5%). In five of the nine patients with progression, total occlusion ensued. In four of the five patients total occlusion occurred within the 45-day interval between the diagnostic and the preangioplasty coronary arteriogram. New or increased preexisting collaterals to the occluded vessel developed in all five patients with total occlusion. None of these patients had clinical or electrocardiographic evidence of myocardial infarction or significant changes in ventricular function. Angiographic evidence of thrombi was seen in ten of 34 patients with unstable angina (29%). We concluded that coronary artery stenosis in patients with unstable angina pectoris is progressive in a significant number after a short time. The cause of progression of coronary stenosis in patients with unstable angina is unknown. Since in a significant number of patients with unstable angina coronary thrombus was suggested by angiography, coronary thrombosis superimposed on coronary atherosclerosis may play a significant role in this syndrome. Further prospective studies are needed, including repeat coronary arteriograms to evaluate the cause of unstable angina, define the role of coronary thrombosis, and evaluate the cause of unstable angina, define the role of coronary thrombosis, and evaluate the efficacy of more aggressive treatment adding the use of prolong heparin and antiplatelet agents prior to coronary angioplasty.

Total occlusion of left main coronary artery without angina pectoris.

A patient had total occlusion of the left main coronary artery that was proved by coronary arteriography. The patient was initially seen with clinical signs of congestive heart failure but without symptoms of angina pectoris or ECG evidence of myocardial infarction. The patient's extensive right-to-left coronary artery collaterals may have contributed to the absence of chest pain. Because of the severe left ventricular dysfunction and the absence of chest pain, the patient was treated with medical therapy. Six months after the cardiac catheterization, he was alive and well under New York Heart Association functional classification II.