Systolic blood pressure response to percutaneous transluminal coronary angioplasty for cardiogenic shock.

This study reports that an improvement in systolic blood pressure of > 10 mm Hg after PTCA in patients with cardiogenic shock was associated with in-hospital survival (8 of 8 patients). Failure to achieve infarct artery patency (6 of 6) or technically successful PTCA, unaccompanied by improved systolic blood pressure in the catheterization laboratory, was associated with in-hospital mortality in this series.

Percutaneous transluminal angioplasty of saphenous vein grafts for medically refractory unstable angina.

OBJECTIVES: We attempted to answer the question, Is balloon angioplasty a reasonable alternative to repeat coronary artery bypass graft surgery in patients with previous coronary bypass graft surgery, medically refractory unstable angina and vein graft lesions? BACKGROUND: Patients with medically refractory unstable angina need revascularization. Patients with previous coronary artery bypass graft surgery and medically refractory angina are at "high risk" for adverse outcomes with repeat coronary bypass graft surgery. Conversely, patients with angioplasty of old vein grafts are also at "high risk" for adverse outcomes. METHODS: Balloon angioplasty of 89 lesions in saphenous vein grafts was performed in 75 consecutive patients with medically refractory unstable angina. Of these 75 patients, 24 (32%) had myocardial infarct within 30 days, 23 (31%) had left ventricular ejection fraction < 0.35, and 50 (67%) had major comorbidity. Patients underwent standard balloon angioplasty with aggressive use of intravenous and intracoronary heparin, urokinase, nitroglycerin, oral aspirin, calcium channel blocking agents and coumadin. RESULTS: Angiographic success (reduction of stenosis < or = 50% without major complication) was seen in 84 of 89 lesions. Clinical success (angiographic success plus hospital discharge without major complication) was seen in 70 of 75 patients. During index hospitalization, two patients (3%) died, two (3%) had nonfatal infarcts, and one (1%) had emergency reoperation (coronary bypass graft surgery). In late follow up (3 to 66 months), 14 (20%) patients were lost to follow-up, 17 (23%) had repeat percutaneous transluminal coronary angioplasty, 2 (3%) had late bypass graft reoperation, 18 (25%) had late death, and 1 (< 1%) had a heart transplant. Of the 41 patients alive after one or more angioplasties, 25 have little or no angina, and 16 have occasional or more angina. We compared long-term survival rate in these 75 patients with a cohort of patients with high risk, unstable angina from the Veterans Affairs Surgical Registry (2,570 patients). The 30-day survival rate was better in patients with coronary angioplasty (97% vs. 92%, p < 0.05), but by 6 months there was no difference, and by 5 years a trend toward a higher survival rate with coronary artery bypass graft surgery was seen. CONCLUSIONS: Balloon angioplasty of saphenous vein grafts with aggressive adjunctive pharmacotherapy is a reasonable alternative to repeat coronary bypass graft surgery in patients with medically refractory unstable angina, previous coronary bypass graft surgery and saphenous vein narrowing.

Salvage angioplasty: an alternative to high risk surgery for unstable angina?

This prospective, Human Subjects Committee and Ethics Committee approved investigation was performed to determine if coronary angioplasty (PTCA) might be a reasonable alternative revascularization method for unstable angina patients thought to be at high risk for operative (CABG) mortality. Between March 1990 and October 1991, thirty-four consecutive patients with medically refractory rest angina were deamed to have high risk of surgical mortality and underwent PTCA without surgical backup. Predicted operative mortality was calculated for each patient based upon the VA Surgical Risk Assessment model. Angioplasty of 52 vessels was attempted. Reduction in lumenal narrowing to < 50% and improved angiographic flow was obtained in 47 vessels. There were four complicating infarctions. One death occurred in the lab, and three patients with unsuccessful angioplasty died within 30 days of pump failure. Relief of angina occurred in 30/34. Thirty patients were discharged home. In follow-up from 1 to 12 months, there have been 2 late sudden deaths at 4 months and 9 months, 1 death from lung cancer; 4 patients have stable exertional angina; 2 are awaiting heart transplant but are pain free, and one patient who had PTCA during cardiogenic shock from acute myocardial infarction had elective coronary artery bypass surgery. There have been no late myocardial infarctions. The observed angioplasty 30-day mortality of 11.8% (95% confidence limit 1% to 22.6%) compares favorably with the predicted operative mortality of 23.8% for this group. This prospective but non-randomized series supports the concept that balloon angioplasty may be a reasonable alternative to surgical intervention in some patients with unstable angina and high risk for surgery. A prospective randomized trial is warranted.

Automated external defibrillators: an update of additions to the ACLS algorithms.

Instruction in the use of the automated external defibrillator is now a mandatory component of ACLS certification. Here's a review of changes to the ACLS algorithm.

Pulmonary vascular impedance and wave reflections in the hypoxic calf.

The alterations in pulsatile hemodynamics that occur during hypoxic pulmonary vasoconstriction have not been well characterized. Changes in oscillatory hemodynamics, however, may affect right ventricular-pulmonary vascular coupling and the dissipation of energy within the lung vasculature. To better define hypoxic pulsatile hemodynamics, we measured main pulmonary artery proximal and distal micromanometric pressures and ultrasonic flow in four open-chest calves during progressive hypoxia. Main pulmonary artery impedance and pressure transmission spectra were calculated using spectral analysis methods. Measured pressure and flow signals were separated in the time domain into forward and backward components. Hypoxia increased pulmonary blood pressure and resistance and produced multiple modifications in the impedance and pressure transmission spectra that indicated increased wave reflections and elasticity. The impedance and apparent phase velocity first-harmonic values were increased in amplitude, and the pressure transmission modulus plot showed an increased peak value. In addition, the impedance modulus plot demonstrated a rightward shift and increased oscillation in the mid- to high-frequency range. The time domain analysis also confirmed increased wave reflections and elasticity. Hypoxia produced large backward-traveling (reflected) pressure and flow waves. The initial portions of these waves arrived at the heart during systole, producing characteristic changes in the measured pressure and flow waveforms. With prolonged hypoxia, main pulmonary artery pulse wave velocity increased by 30%. Thus, hypoxia is associated with complex alterations in pulmonary artery elasticity and wave reflections that act to increase the oscillatory afterload of the right ventricle.