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Biomedical subjects

G Schimert

Publications and source records attributed to G Schimert.

At least 19 recordsLinked to original sources

Left thoracotomy reoperation for coronary artery disease.

Twenty patients underwent reoperative coronary artery bypass grafting (CABG) through a left thoracotomy since 1971. This was their second CABG in 16 patients, third in three patients and fourth in one patient. Surgery was performed from 1 to 16 years following the initial procedure. Demographic data showed no significant variation from patients undergoing standard reoperative CAGB in this institution. Ejection fraction varied between 30% and 73%. Cardiopulmonary bypass technic has gradually developed since 1971, using the left femoral artery and vein. For venous cannulation a 50-cm long catheter was positioned in the right atrium. Monitoring included pulmonary artery catheter with oximetry. Fibrillatory arrest of the heart was utilized with 18-33 degrees C core cooling cardioplegia. The left internal mammary artery (6) and reverse saphenous veins (44) were used for an average of 2.5 grafts per patient. The proximal anastomosis was placed on the descending thoracic aorta or the left subclavian artery. There were two early and no late deaths. Sixteen patients were restudied before discharge from the hospital with an early graft patency rate of 98% (41/42). The left thoracotomy approach may be preferable in selected cases of redo CABG. The danger of damage to the heart and patent grafts is greatly reduced.

Aged

Combined antegrade/retrograde cardioplegia for myocardial protection: a clinical trial.

The role of retrograde coronary sinus perfusion in the preservation of ischemic myocardium is controversial. We evaluated the use of combined antegrade and retrograde cardioplegia in 59 patients undergoing coronary artery bypass surgery. Nineteen patients were administered antegrade cardioplegia, whereas 40 patients were administered antegrade plus retrograde cardioplegia. Hemodynamic data were obtained before the onset of cardiopulmonary bypass and at 1, 2, 4, 8, 16, and 24 hours after cessation of cardiopulmonary bypass. Myocardial function was assessed by measuring systemic blood pressure, heart rate, cardiac index, pulmonary artery pressure, and capillary wedge pressure. Both cohorts were similar in age, incidence of hypertension, diabetes, and previous myocardial infarction. No significant differences were noted in the need for postoperative inotropic support, the incidence of postoperative arrhythmias, myocardial infarction, heart block, or death. The two groups were similar with respect to cardiac index and systemic and pulmonary vascular resistance. However, the left ventricular stroke work index, when expressed as a function of its prebypass control value, was significantly improved (p less than 0.01) in the cohort administered combined cardioplegia. In the combined group recovery of left ventricular stroke work index occurred earlier and was more complete. These results suggest that the use of combined antegrade/retrograde cardioplegia is safe and may provide superior protection.

Aged

Clinical advantages of papaverine cardioplegia.

To determine the efficacy of papaverine in improving myocardial protection by causing a uniform distribution of the cardioplegic solution, a prospective study was carried out in 200 consecutive patients undergoing various open heart procedures. Several parameters (creatine kinase MB, electron microscopy of myocardium, perioperative myocardial infarction rate, frequency of postoperative arrhythmias) were monitored and compared with those of a control group which consisted of the previous 200 consecutive patients in whom the same cardioplegic solution was used, but without papaverine. In the papaverine group the operative mortality due to low cardiac output was 0.5% compared to 3%, and the spontaneous recovery of the heart after release of the aortic cross-clamp was 89% compared to 47% in the control group (P less than 0.01). The perioperative myocardial infarction rate was 5% and the incidence of postoperative temporary arrhythmias was also 5% in the papaverine group, while in the control group the perioperative myocardial infarction rate was 10% and the postoperative arrhythmia incidence was 13% (P less than 0.01).

Adolescent

Influence of length of aortic occlusion with cold potassium cardioplegia on early and late mortality in cardiac valve replacement.

This study determines if prolonged aortic crossclamp time (ACC) with the use of cold potassium cardioplegia during elective cardiac valve replacement contributed to the risk of operative mortality in 225 patients. In Group I (143 patients), the ACC was less than 120 minutes (mean 86) and in Group II (82 patients), it was greater than 120 minutes (mean 146). The preoperative variables showed that Group II contained more severely ill patients who were undergoing more complex operations than in Group I. The operative mortality rate was 7% in Group I and 10% in Group II (p = not significant). Postoperative inotropic support was required in 13% of Group I and 30% of Group II patients (p less than 0.005). Operative mortality in patients in New York Heart Association (NYHA) functional class I and II was 0 and in patients in classes III and IV it was 13% (p less than 0.00008). Five percent of patients in NYHA classes I and II and 32% in classes III and IV required inotropic support (p less than 0.000005). The actuarial survival at 60 months was 88 +/- 3% for Group I and 77 +/- 7% for Group II (NS). For the NYHA class I and II patients, however, it was significantly better (98 +/- 2%) than class III and IV patients (75 +/- 5%) (p less than 0.0001). Analysis by logistic equation revealed that the NYHA functional classes III and IV were significant incremental risk factors for probability of in-hospital mortality (p less than 0.0001) but not the ACC time (p greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Improved cardiovascular hemodynamics with atrioventricular sequential pacing compared with ventricular demand pacing.

To determine the advantages of atrioventricular (AV) sequential pacing over ventricular demand pacing, paired cardiovascular hemodynamic studies were performed in each pacing mode at a constant heart rate. The paired studies included determination of ejection fraction (EF) by echocardiography and gated blood pool radionuclide scanning, and of cardiac output (CO) by the indicator-dilution method. There was no significant difference in EF with either pacing mode. Determined by echocardiography, EF with AV sequential pacing was 57% compared with 56% with ventricular demand pacing; by the gated blood pool method, EF with AV sequential pacing was 58% compared with 57% in the ventricular mode. Significant improvement with AV sequential pacing was seen in CO (4.75 L/min from 3.75 L/min; p less than 0.01); stroke volume (58 ml from 48 ml; p less than 0.02); arteriovenous oxygen content difference (4.9 vol% from 5.6 vol%; p less than 0.01); total peripheral resistance (1,724 dynes sec cm-5 from 2,025 dynes sec cm-5; p less than 0.01); and cardiac contractility, as reflected by mixing time (6.9 seconds from 8.0 seconds; p less than 0.02). No significant changes were noted in mean arterial or atrial pressure or in systemic oxygen consumption. In a second group of 6 patients, similar paired studies were done in AV sequential pacing modes before and after therapeutic reduction of total peripheral resistance. A significant increase in CO (43%) was observed following reduction in total peripheral resistance. We conclude that AV sequential pacing improves CO more effectively than ventricular demand pacing. Cardiac output can be further enhanced in patients with congestive heart failure by pretreatment with agents to reduce total peripheral resistance.

Adult

Early history of familial hypophosphataemic vitamin D-resistant rickets. Report of three cases observed since birth.

Three patients with familial hypophosphataemic vitamin D-resistant rickets (FHR) born to affected mothers have been clinically, radiologically and biochemically observed since birth. The value of the different early diagnostic signs is evaluated, and the efficiency of early phosphate and vitamin D treatment is discussed. Our observations suggest the following conclusions: Infants of FHR affected mothers can be diagnosed as having the disease by careful physical examinations and by a pathological increase of serum alkaline phosphatase with normal serum calcium, before radiological signs of rickets occur. The serum phosphate concentrations in early infancy are variable and of little or no diagnostic help. Early treatment is useful to cure or even to avoid rickets and to normalize serum alkaline phosphatase, but not hypophosphataemia. In spite of some favorable results, the influence of early started treatment on growth and leg deformities is difficult to assess due to the variations of individual expressivity of the disease.

Alkaline Phosphatase

Long-term survival after coronary bypass surgery. Comparison of various subsets of patients with general population.

Life-table analysis consecutive cases of isolated coronary bypass surgery at the Buffalo Hospital between 1973 and 1977 showed an estimated survival of 94 per cent at five years, equal to that of an age- and sex-matched group of the US population. Subsets of these patients divided according to sex, age, number of vessels narrowed, number of segments grafted, history of myocardial infarction, ejection fraction, and presence of unstable angina have estimated survivals not statistically less in any of these subsets than that of matched cohorts of the general population.

Adult

[Field trial with a new betablocker (Solgol)].

In a field trial with nadolol (Solgol) in 14.870 unselected hypertensives, the blood pressure was lowered to the limit or normal range in 59.5%, in 32.4% the normal range was attained with daily doses of 60-240 mg (once daily). Also on changing over from other antihypertensives and betablockers there was a further lowering of blood pressure. This is more marked diastolically (77% of 4.604 diastolic hypertensive patients) and did not decrease with age, in contrast to other betablockers. Whether this peculiar action of nadolol is based on the increase of renal circulation demonstrated for this preparation or on the other hand on the behavior of the peripheral resistance is discussed. In 87% of the patients doses of d1-2 mg/kg body weight, corresponding to 60-120 mg once daily were sufficient to reduce the blood pressure satisfactorily. The preparation is characterized by a long halflife (20-24 hours) and good tolerance.

Adrenergic beta-Antagonists

Cold blood--potassium cardioplegia.

A technique is described for providing myocardial protection utilizing oxygenated blood that is drawn from the pump oxygenator and passed through two disposable cardioplegic cooling coils, which are joined in series and submerged in ice slush. A potassium-containing cardioplegic solution is run into the oxygenated blood at the level of the cooling coils. The amount of blood used in the blood-potassium cardioplegic mixture is controlled using a screw clamp. This method has been used with excellent results in 150 consecutive patients undergoing aortocoronary saphenous vein bypass grafting.

Blood

Refinements in coronary artery surgery contributing to improved survival.

Reviews of the literature and controlled studies of medical versus surgical treatment of coronary artery disease that include surgical results from 3 or 4 years ago may not be pertinent to therapeutic decisions made today. The results in our patients operated during 2 two-year periods (1974--1976, Group I and 1976--1978, Group II) are compared. The Group II patients had more severe coronary artery disease. They had significantly more grafts per patient (p less than .001), their cardiopulmonary bypass time was significantly reduced (p less than .001), they received less inotropic support (p less than .005) and spent less time in the intensive care unit (p less than .001). There was a significant decrease in the overall perioperative mortality (30-day) in the patients of Group II (p less than .055). The second two-year period coincided with the adoption of refinements in the intraoperative preservation of myocardium and also in surgical technique. These refinements are discussed in detail.

Adult

The revival of the horseshoe graft (side-to-side saphenous-vein-to-aorta anastomosis).

The technique of the horseshoe graft, side-to-side saphenous-vein-to-aorta anastomosis, using a long saphenous vein harvested from the leg is described in this communication. The lack of valves between the ankle and the knee and the high caliber natural Y distributions make this technique attractive. Constructing a double set of vein graft provides, in particular, unlimited possibilities for the construction of six to eight grafts if this appears anatomically feasible.

Coronary Artery Bypass

Dacron patch enlargement of anterior wall of left ventricle after aneurysmectomy with concomitant infarctectomy.

The basis for left ventricular aneurysmectomy with cardiopulmonary bypass was established 20 years ago. There is a higher risk in patients who undergo operation within 2 months of myocardial infarction. In these patients there may be no clear demarcation between devitalized tissue and residual healthy myocardium. A case is reported in which anterolateral aneurysmectomy with concomitant infarctectomy so compromised left ventricular size that the anterolateral wall of the left ventricle had to be reconstructed with a Dacron patch graft.

Adult

Decompression of the heart with siphon drainage.

A simple technique for inducing intracavitary hypothermic cardioplegia and decompressing the left heart through the ascending aorta is presented. The technique is based on siphon drainage, which eliminates the dangers of air embolism.

Cardiac Catheterization

Detection of creatine kinase BB isoenzyme in sera of patients undergoing aortocoronary bypass surgery.

Creatine kinase BB isoenzyme (CK-BB) was detected intraoperatively in 22 of 25 patients undergoing aortocoronary bypass surgery, both in the coronary sinus and in the mixed venous blood. In a group of 10 patients in whom selective intracavitary profound hypothermic arrest was used, CK-BB values were lower than in another group of 10 patients, in whom controlled ventricular fibrillation with moderate total body hypothermia was instituted. This latter group also had higher levels of CK-MB. Patients who developed acute myocardial infarction immediately prior to or during the surgical intervention had the highest CK-BB values. This enzyme appeared as early as 15 minutes after the institution of cardiopulmonary bypass and disappeared within 6 hours. It is considered that part of the BB isoenzyme in serum of patients undergoing heart surgery is of myocardial origin.

Adult

Early and long-term effects on direct myocardial revascularization on cardiac function: a prospective study using multivariable physiological analysis.

Perioperative and late follow-up hemodynamic cardiovascular studies to assess the effects of direct myocardial revascularization on cardiac function objectively have been completed on 51 patients. Analysis of the data delineated three distinct groups basedon the patterns of their early postoperative recovery. Group I patients (12) had a hyperdynamic cardiovascular response to operation and returned to a normal physiological range of cardiac function within 24 hours. Group II patients (24) initially had moderate to severe myocardial decompensation postoperatively but responded to inotropic support and moved into the normal physiological range within 24 to 48 hours. Group III patients (15) had severe, prolonged myocardial decompensation with little response to inotropic support. There were no early deaths in Group I, 1 early iatrogenic death in Group II, and 2 deaths from sepsis, 1 in Group I and 1 in Group II. All 7 cardiogenic deaths occurred in Group III patients. Late follow-up studies 4 to 23 months postoperatively have been completed on 29 patients. These showed cardiovascular stability in the mean values in Groups I and II. Significant improvement in mean cardiac function was seen in surviving Group III patients.

Adult