PubMed Health⌕ Search

Biomedical subjects

R J Krone

Publications and source records attributed to R J Krone.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effect of infarct location on the in-hospital prognosis of patients with first transmural myocardial infarction.

We studied the in-hospital prognosis of 1105 patients who had their first transmural myocardial infarction; 611 patients (55.3%) had anterior myocardial infarction (AMI) and 494 (44.7%) had inferior myocardial infarction (IMI). Patients with IMI had a significantly lower in-hospital mortality rate (9.1% vs 15.6%, p = 0.0014) and significantly lower prevalences of congestive heart failure (39.4% vs 47.6%, p = 0.0066), cardiogenic shock ( 8.7% vs 12.6%, p = 0.0384) and conduction defects (left anterior hemiblock, right bundle branch block and intraventricular conduction defect). The patients with AMI had significantly higher peak enzyme levels, and a greater percentage of them (40.1% vs 25.9%) had SGOT greater than 240 IU/l, whereas more patients with IMI (34.6% vs 27.8%) had SGOT less than 120 IU/l (p = 0.0001). When the parallel subgroups were compared according to the peak SGOT levels (less than 120, 120-240, and greater than 240 IU/l, the differences in the mortality and morbidity between the two infarct locations diminished. However, patients with AMI still had a less favorable outcome. Logistic regression analysis demonstrated that both the peak enzyme level and the infarct location had an independent influence on the in-hospital prognosis of patients with first transmural infarction.

Aged↗
PubMed1982

Urgent myocardial revascularization for dissection of the left main coronary artery: a complication of coronary angiography.

Acute subintimal dissection of the left main coronary artery (LMCA) is a rare but devastating complication of selective coronary angiography. The compromise of the coronary blood flow to an extensive area of myocardium becomes clinically evident in most patients shortly after the injury. Three patients who had catheter-induced LMCA dissection were successfully managed with aorta-coronary artery bypass. We recommend that urgent myocardial revascularization using standard techniques should be carried out in all patients following this injury.

Aged↗
PubMed1981

Influence of recording scale on determination of left ventricular end-diastolic pressure.

Left ventricular (LV) pressure waveforms for 20 beats, originally recorded at 200 scale (200 torr/10 cm) were rescaled by a computer system to represent the identical beats recorded at 40 scale (40 torr/10 cm). Both the original and the rescaled beats were independently evaluated by eight cardiologists who were unaware of the nature of the manipulated data. For each beat the average left ventricular end-diastolic pressure (LVEDP) identified by the eight cardiologists was higher when analyzed on the 200 scale, with an average difference of 2.8 torr (P Less Than 0.001). This scale-dependence of pressure analysis has implications for the development of automated pressure analysis algorithms and for physician review of computer-determined LVEDP data points.

Blood Pressure↗
PubMed1981

The effectiveness of antiarrhythmic agents on early-cycle premature ventricular complexes.

Twelve patients completed a double-blind, crossover antiarrhythmic drug trial in which 300 mg of quinidine, 500 mg of procainamide, 100 mg of phenytoin, or placebo was given four times daily on subsequent weeks. Analysis of 24-hour Holter tapes with a computerized analysis system (Argus/H) permitted accurate counting of premature ventricular complexes (PVCs) subclassified according to coupling interval. No antiarrhythmic agent demonstrated a significant overall reduction in the number of PVCs, but both quinidine and procainamide showed a statistically significant (p less than 0.05) reduction of PVCs with coupling intervals less than 400 msec. This effect was noted both in isolated PVCs (quinidine only) and in PVCs that were part of a couplet or run (both drugs). These findings demonstrate that clinically important effects of procainamide and quinidine can occur in the absence of an overall reduction in the number of PVCs.

Aged↗
PubMed1980

An improved snare system for the nonsurgical retrieval of intravascular foreign bodies.

We have modified a snare technique originally described for transcolonoscopic removal of colonic polyps for the retrieval of intravascular foreign bodies. The key difference from other snare techniques is the employment of a wire snare with a crimp in its midportion that enables the formation of a loop in a plane perpendicular to the axial direction of the guiding catheter. With this technique we have quickly removed a variety of objects from the right heart and pulmonary arteries in four patients.

Blood Vessels↗
PubMed1980

In-hospital prognosis of patients with first nontransmural and transmural infarctions.

We studied the in-hospital mortality and morbidity of 745 patients who had suffered a first myocardial infarction. One hundred twenty-four patients (16.6%) had nontransmural infarction and 621 (83.4%) had transmural infarction. Both groups of patients were similar in the distribution of age, sex, and coronary risk factors. Patients with nontransmural infarction had a significantly lower mortality (3% vs 11%, p less than 0.01) and a lower prevalence of premature ventricular complexes (81% vs 88%, p less than 0.05). The patients with transmural infarction were distributed evenly among the three subgroups with peak SGOT levels less than 120 units, 120-240 units and more than 240 units (31%, 34% and 35%, respectively), while most patients with nontransmural infarction (60%) had peak SGOT levels less than 120 units (p less than 0.0001). When the in-hospital mortality and morbidity were compared between the parallel subgroups, the prognosis of patients with the two types of infarctions was similar. This study shows that the peak SGOT level is more important than the type of infarction in determining the acute mortality and morbidity of first myocardial infarction.

Acute Disease↗
PubMed1979

Epicardial pacemaker complicated by cardiac tamponade and constrictive pericarditis.

Following insertion of an epicardial pacemaker, our patient developed cardiac tamponade complicated by subacute constrictive pericarditis. Echocardiographic findings and intracardiac pressures were typical of constrictive pericarditis, which was confirmed at surgery. Although rare, these unusual complications should be considered in patients who develop evidence of reduced cardiac output following either transvenous or epicardial electrode placement.

Aged↗
PubMed1977

A simple, inexpensive technique to permit the half-axial projection in laboratories with single plane cineangiography.

A simple inexpensive modification to permit x-ray beam angulation of a cineradiographic system consisting of a ceiling-suspended image intensifier and an under-the-table x-ray tube is described. This has permitted the incorporation of the half-axial projection into the routine evaluation of the proximal left anterior descending artery (LAD) with a minimum of patient discomfort.

Cineangiography↗
PubMed1976

Severe coarctation of the aorta with pulmonary edema. An unusual presentation of a traumatic aortic aneurysm.

A patient with an unrecognized rupture of the ascending aorta developed severe pulmonary edema three weeks following the initial injury. This is a distinctly unusual manifestation of this injury. Emergency resection of the traumatic aneurysm was required to reverse the rapidly deteriorating clinical situation. The early recognition and surgical treatment of this lesion would have avoided this complication.

Adult↗
PubMed1976

Surgical treatment of unstable angina by saphenous vein and internal mammary artery bypass grafting.

During a 3 year period, direct myocardial revascularization was performed on an urgent basis in 48 patients with intermittent resting chest pain which persisted more than 24 hours despite in-hospital medical therapy and was accompanied by electrocardiographic changes representative of ischemia. Sixteen patients had saphenous vein (SV) grafts exclusively, and 32 patients each had one or two internal mammary artery (IMA) grafts with or without additional vein grafts. Follow-up ranges from 5 to 41 months (mean, 22 months). Twelve patients had single grafts to the left anterior descending coronary artery (LAD), 18 had double grafts, 16 had triple grafts, and 2 had quadruple grafts. The LAD required grafting in every patient. There was one operative death (2 per cent) and one late death from noncardiac causes. There were two (4 per cent) early postoperative myocardial infarcts and no late infarcts. Actuarial analysis projects a survival rate of 96 per cent 3 years postoperatively. Eighty-one per cent of the survivors are in Functional Class I, 17 per cent are in Class II, and 2 per cent are in Class III. All patients had postoperative angiography 2 weeks after operation. Eighty-six per cent of the SV grafts and all IMA grafts were open. No significant differences were observed between mean preoperative and postoperative left ventricular end-diastolic pressures or ejection fractions, but these parameters were noted to improve after operation in several patients. The remarkably high early and late survival rates, the low incidence of myocardial infarction, and the excellent functional results after rather long follow-up indicate that emergency coronary revascularization provides an effective therapy for unstable angina. The use of IMA grafts, when feasible, is a safe and possibly preferable approach in these patients.

Adult↗
PubMed1975

Selection of coronary bypass. Anatomic, physiological, and angiographic considerations of vein and mammary artery grafts.

Results of direct coronary revascularization with 511 grafts in 213 patients from 1971 to 1974 are reviewed. To improve an early saphenous vein graft (SVG) patency of 84 per cent in the first 85 patients, we have used internal mammary artery grafts (IMAG), when possible, since January, 1973. In 1973 to 1974, 15 patients had SVG's only (36 grafts) and 113 received one or two IMAG's with or without additional SVG's (total 282 grafts); in 26 we used a crossed double IMAG. Forty-seven of 48 patients with unstable angina survived and did well. Flows in SVG's and IMAG's were comparable. Flows in right IMAG's to diagonal or marginal vessels were higher than in right IMAG's to right or left anterior descending (LAD) vessels. In 12 patients with both SVG and IMAG, there was no difference in flow response of either graft to vasoactive drugs. Survival, functional, and patency results with IMAG's were as good as or better than results with SVG's. We conclude that IMAG's yield higher patency and comparable flow rates to SVG's and should be used when the IMA approximates the recipient artery in size and when a high pulsatile free flow is measured from the end of the graft. IMAG's are also safe and feasible for unstable angina.

Adult↗