Efficacy of hepatobiliary imaging of acute abdominal pain: concise communication

To assess prospectively the usefullness of hepatobiliary imaging in acute abdominal pain (72 hr or less), 36 patients were scintigraphed after intravenous injection of 5 mCi of Tc-99m p-isopropyl-iminodiacetic acid (PIPIDA). Before the procedure, the referring physician completed Part I of a questionnaire indicating his differential diagnosis, diagnostic confidence (expressed as a percentage), and therapeutic plan. Immediately after the test, the same physician, with knowledge of the results, completed Part II of the questionnaire indicating again his differential diagnosis, diagnostic confidence, and therapeutic plan. The impact of the imaging on the physician's diagnositic confidence was expressed as a log-likelihood-ratio (LLR). The mean LLR for this series was 1.48 +/- 0.93, with 33 of 36 (92%) patients demonstrating a LLR greater than 0.0. In 26 of 33 patients, a LLR greater than 1.0 was achieved; and in 11 of 36 patients, a change in the physician's therapeutic plan occurred, reflecting the considerable impact of hepatobiliary imaging on the decision-making process.

Sustained benefits or oral pentaerythritol tetranitrate on ventricular function in chronic congestive heart failure

The hemodynamic effects of a single oral dose of 80 mg of pentaerythritol tetranitrate (PETN) were determined over a 5-hr period in 16 patients with chronic congestive heart failure. PETN decreased (p < 0.05) pulmonary capillary wedge pressure (27 to 18 mm Hb), right atrial pressure (15 to 9 mm Hg), mean systemic arterial pressure (89 to 80 mm Hg), and systemic vascular resistance (1,812 to 1,466 dynes x sec x cm-5). There were increases (p < 0.01) in cardiac index (2.0 to 2.3 l/m2/min), stroke volume index (24 to 28 ml/m2), and stroke work index (25 to 31 gm-m/m2). Peak reduction in pulmonary capillary wedge pressure occurred 2 hr after PETN and hemodynamic effects were still apparent at 5 hr. In nine patients in whom left and right ventricular ejection fractions were determined by radionuclide ventriculography before and after PETN, no changes were found in left ventricular ejection fraction (0.20 to 0.22, p = NS) although there was a modest increase in right ventricular ejection fraction (0.29 to 0.34, p < 0.05). The data indicate that oral PTEN may induce beneficial effects on preload and afterload in congestive cardiac failure that may last 5 or more hours.

Sustained beneficial effects of oral pentaerythritol tetranitrate on ventricular function in chronic congestive heart failure

The hemodynamic effects of a single oral dose of 80 mg of pentaerythritol tetranitrate (PETN) were determined in 16 patients with chronic congestive heart failure over a 5-hour period. PETN produced significant (p < 0.05) decreases in pulmonary capillary wedge pressure (27 to 18 mmHg), right atrial pressure (15 to 9 mmHg), mean systemic arterial pressure (89 to 80 mmHg) and systemic vascular resistance (1812 to 1466 dynes . sec . cm-5). There were significant increases (p < 0.01) in cardiac index (2.0 to 2.3 l/m2/min) stroke volume index (24 to 38 ml/m2) and stroke work index (25 to 31 gm-m/m2). The peak reduction in pulmonary capillary wedge pressure occured two hours after PETN administration and the hemodynamic effects were still apparent at fivae hours following drug ingestion. In nine patients in whom left and right ventricular ejection fractions were determined by radionuclide ventriculography before and after administration of PETN, no significant changes were found in left ventricular ejection fraction (0.22 to 0.24, p. = NS) although a modest increase was noted in right ventricular ejection fraction (0.29 to 0.34 p < 0.05). The data indicates that orally-administered pentaerythritol tetranitrate may produce beneficial effects on preload and afterload in congestive cardiac failure, the duration of which may be five hours or longer.

Hemodynamic effects of intravenous timolol in coronary artery disease

The hemodynamic effects of intravenous timolol were evaluated in 20 patients with coronary artery disease during diagnostic cardiac catheterization. The threshold dose of 0.25 mg reduced heart rate and cardiac index by 15% (p less than 0.05), left ventricular work index by 21% (p less than 0.05), and left ventricular dp/dt by 16% (p less than 0.05) while increasing left ventricular end-diastolic pressure by 49% (p less than 0.01), mean pulmonary arterial pressure by 17% (p less than 0.01), and systemic vascular resistance by 16% (NS). Larger doses (0.5 mg and 1.0 mg) induced similar responses with a greater effect on systemic vascular resistance (+22%, p less than 0.01, and +31%, p less than 0.001). The mean arterial pressure and stroke volumes were not affected by timolol. Peak effects, occurring at about 10 min after drug injection, did not correlate with plasma levels. The overall hemodynamic effects of timolol were similar to those reported for equipotent doses of propranolol and could be accounted for by the beta-adrenoceptor blocking activity.

Quantification of myocardial injury during coronary artery bypass graft

Serial intraoperative myocardial-specific creatine-kinase (MB-CK) samples were obtained in 32 patients undergoing coronary artery bypass graft (CABG). Based upon their postoperative ECG and technetium pyrophosphate SCAN results, each patient was classified as either Group A (MI), B (normal), or C (equivocal). Peak MB-CK was reported for each group. The mean value for Group A (75 +/- 17 IU/L) is higher than for Group B (18 +/- 1 IU/L) or Group C (30 +/- IU/L). The concept of measuring and a formula for calculation of intraoperative myocardial injury are presented. The mean value for Group A (MI, 10,709 +/- 5885) is higher than either groups B (normal) or C (equivocal) by a test of proportionality (P < 0.001). Likewise, Group C (898 +/- 159) is higher than B (466 +/- 71) (P < 0.05). This index, while in need of further validation, corresponds closely to the clinical status of the 32 patients studied and should provide a means more refined than mortality or incidence of MI upon which to judge efficacy of any proposed means of operative myocardial preservation.

Coronary sinus blood flow and sampling for detection of unrecognized myocardial ischemia and injury

Fifteen patients were studied to detect unrecognized intraoperative ischemia or necrosis in perioperative myocardial infarction (MI) associated with coronary bypass. Simultaneous arterial and coronary sinus blood samples were analyzed for lactate and both total and MB-CPK. Coronary sinus flow measurements were done coincident with sampling in seven patients. Five had perioperative MI diagnosed by positive pyrophosphate scan and electrocardiogram. Although normal initially (mean 19 +/- 5.0%), lactate extraction after thoracotomy, before aortic cross-clamping, became abnormal in 12 patients with more pronounced abnormality in those with perioperative MI (-19 +/- 9.0%). Net efflux of lactate was higher in perioperative MI (mean 0.6 +/- 0.2 vs 0.016 +/- 0.04 mM/L) than in non-MI patients. All patients had detectable total and MB-CPK (mean 295 and 31 IU/L, respectively) and all those with coronary disease had a positive arterial-coronary sinus gradient for MB-CPK (mean 9 IU/L). Perioperative MI patients had a higher gradient than non-MI patients (mean 25 vs 2 IU/L) and with one exception that gradient exceeded 5-7 IU/L. It is concluded that severe ischemia before aortic cross-clamping precedes perioperative MI and may contribute to release of CPK into coronary sinus blood. Improvement in the techniques of anesthesia and intraoperative myocardial preservation are suggested.