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Biomedical subjects

H B Barner

Publications and source records attributed to H B Barner.

At least 145 records · Page 8Linked to original sources
PubMed1979

Cold blood cardioplegia.

The technique of myocardial protection by means of a cardioplegic solution consisting of cold blood (10 degrees C) with potassium (30 mEq. per liter) is described. A disposable cooling coil is used and a separate pump head for coronary perfusion is avoided. The aortic perfusion cannula can be used for venting of the left ventricle and subsequently for venting of air. This method was used in 125 consecutive patients undergoing coronary revascularization and in 73 consecutive pediatric cardiac surgical procedures with excellent results.

Blood↗
PubMed1979

Cold-blood potassium cardioplegia: evaluation of glutathione and postischemic cardioplegia.

Potassium (34 mEq/L) cardioplegia was induced with cold blood (CBK) in three groups of six dogs undergoing 60 minutes of myocardial ischemia at a systemic temperature of 27 degrees +/- 2 degrees and a myocardial temperature of 7 degrees +/- 2 degrees C (crushed ice). Group 1 (CBK) animals were reperfused initially with 400 ml cold blood over 8 to 10 minutes at increasing pressures of up to 75 mm Hg. Group II (CBK-K) dogs were reperfused in the same manner as Group I with the addition of potassium chloride, 30 mEq/L. In Group III (CBKG-KG) glutathione, 30 mg/100 ml, was added to both the pre- and postischemic perfusions with CBK. After 30 minutes of reperfusion control studies were repeated. Heart rate, peak systolic pressure, rate of rise of left ventricular pressure, maximum velocity of contractile element, pressure-volume curves, coronary flow distribution, muscle stiffness, and heart water were not significantly different from control values. Total coronary flow and myocardial uptake of oxygen, lactate, and pyruvate did not serve to separate the three groups; the same was true for right ventricular creatine phosphate, adenosine triphosphate, and adenosine diphosphate during ischemia and recovery. Ultrastructural myofibrillar lesions were noted in all groups. thus, postischemic cardioplegia and use of a physiological reducing agent do not enhance CBK cardioplegia with topical and systemic hypothermia.

Adenosine Diphosphate↗
PubMed1978

Coronary revascularization under age 40 years. Risk factors and results of surgery.

Groups of patients such as the elderly, the diabetic and women have been studied to evaluate the effectiveness of coronary revascularization. In this report 77 patients under age 40 years undergoing coronary revascularization were studied. There was a high prevalence rate of predisposing factors. Sixty-eight percent reported a family history of heart disease and 27 percent a history of diabetes; 57 percent were hypertensive, 43 percent were overweight, 91 percent smoked, 5 percent were diabetic and 16 percent had abnormal glucose tolerance curves. Sixty-four percent had hypercholesterolemia (cholesterol 250 mg/100 ml) and 56 percent hyperlipidemia. Forty-four percent had had a previous myocardial infarction; 95 percent had angina pectoris, 12 percent preinfarction angina and 9 percent congestive cardiac failure. There were no operative deaths. The incidence rate of perioperative myocardial infarction (new Q waves in the electrocardiogram) was 4 percent. The mean length of of follow-up was 26 months (range 6 months to 5 years). The late mortality rate was 4 percent. Eight percent had a late myocardial infarction. Overall graft patency was 85 percent. Sixty-seven percent of patients were free of angina, and 17 percent were in improved condition. Seventy-one percent returned to work, while 29 percent remained unemployed. This study shows that in young patients, coronary revascularization is associated with low mortality and morbidity rates and that, despite the wide prevalence of predisposing factors, the prognosis and graft patency rate of these patients are similar to those of other groups.

Adult↗
PubMed1978

The Blalock-Taussig shunt in the neonate.

With improvements in the techniques of microvascular surgery, the Blalock-Taussig shunt has been applied to smaller infants. We report our experience in 17 neonates (mean age 9 days, mean weight 3.2 kg) who underwent emergency shung operations. The early mortality was 17.6% (3 of 17), with only 1 death (7%) from renal failure and sepsis, in the last 14 patients. Three shunts were patent but inadequate and required a secondary procedure, which was successful in all 3. There were 3 patients with late shunt failures at a mean of 15 months postoperatively, while 2 are still doing well at 15 and 18 months. No patients developed congestive cardiac failure. The late mortality was high (5 of 14), but was due to late shunt failure and was preventable in only 1 patient. These results are encouraging, and we continue to perform the Blalock-Taussig shung in neonates. It is hoped that improvements in technique will reduce the incidence of inadequate shunts.

Adolescent↗
PubMed1978

A simple method of cold coronary perfusion.

Hypothermic coronary perfusion lengthens the safe duration of anoxic arrest. Intermittent selective hypothermic coronary perfusion provides extended myocardial protection. We describe a method of achieving profound myocardial hypothermia by selective deep hypothermic coronary perfusion using a cooling coil without a separate pump head.

Adult↗
PubMed1978

Myocardial revascularization in women.

During the period January, 1970, through June, 1977, 1,541 patients underwent coronary artery bypass grafting; 241 of them were women (15.6%). Operative mortality rates for the entire study were 2.4% in men and 3.7% in women, but they showed a marked decline in women during 1975 to mid-1977, with only 2 deaths in 140 patients (1.4%). Women comprised a larger percentage of patients (16.7%) in these later years. Women were slightly older, received fewer grafts, had better preservation of ventricular function on preoperative studies, and had more severe anginal symptoms than men. Patency rates were significantly lower in women at 1 month, 1 year, and 3 years. Five-year survival was not significantly different between women (88.3%) and men (93.5%). Many of these findings may be explained on the basis of women having smaller coronary arteries than men. These favorable results differ from earlier reports of higher mortality rates in women and indicate that myocardial revascularization should not be withheld from female patients.

Age Factors↗
PubMed1978

Topical cardiac hypothermia: the effect of methylprednisolone sodium succinate.

We evaluated the effects of methylprednisolone sodium succinate (MPSS) on 60 minutes of myocardial ischemia during profound (5 degrees C) topical cardiac hypothermia (ice chips) in a canine right heart bypass preparation. The ventricular function curve shifted to the right and downward, but not significantly, after ischemia, and stroke work declined significantly for both control and treated dogs. Contractility (rate of rise of left ventricular pressure and maximum velocity of the contractile element) declined for both groups but not significantly. Total coronary flow, oxygen consumption, and metabolism of lactate and pyruvate were not different for control and treated dogs. Ultrastructure of the outer and inner myocardium did not demonstrate benefit from MPSS. Intracellular and extracellular edema of moderate severity was slightly worse in the subendocardium, and reversible mitochondrial injury of a mild to moderate degreee was symmetrically present. Ice-related injury was not noted. We were unable to deomonstrate that pretreatment with MPSS favorably alters cardiodynamics or ultrastructure after 60 minutes of profound topical cardiac hypothermia.

Animals↗
PubMed1978

Late sequelae of perioperative myocardial infarction.

The late suquelae of myocardial injury occurring at the time of direct myocardial revascularization are unknown. Fifty of 500 consecutive patients undergoing aortocoronary bypass grafting developed both electrocardiographic and enzymatic evidence of myocardial injury. They were matched with 50 patients of similar age, sex, history of previous infarction, severity of angina, degree of coronary arteriosclerosis, and level of ventricular function as determined by preoperative angiographic studies. The conduct of the operation was identical in each group except for prolongation of total cross-clamp time in those patients with myocardial injury. The total number of vessels grafted, the conduit used, and the operative mean graft flow were similar. Results of treadmill stress testing at 24 to 36 months were not significantly different between groups. Angina status, long-term survival, graft patency, and ventricular function were not adversely affected by intraoperative myocardial injury. However, postoperative ventricular function and stress test performance were related to graft patency.

Adult↗
PubMed1978

Myocardial revascularization: a rebuttal of the cooperative study.

From January 1972 through December 1974, at Saint Louis University Medical Center (SLU), 345 patients similar to those of the VA Cooperative Coronary Artery Study received CABG. Operative mortality was SLU 2.3%, VA 5.6% (p < 0.05). Perioperative myocardial infarction rate was SLU 8.4%, VA 18% (p < 0.005). One year graft patency was SLU 87%, VA 71%; all grafts patent SLU 76%, VA 54%; at least one graft patent SLU 96%, VA 89%. SLU angina pectoris relief at five years was 90%. SLU patients free of myocardial infarction five years postoperatively was 83%. Comparative cumulative four year survivals were: [Table: see text] Cumulative four-year survival in 272 SLU patients (79%) completely revascularized was 94%, compared to SLU entire group of 95%, VA medical 86% (p < 0.002) and VA surgical 85% (p < 0.002). Comparing 1972-74 SLU results to VA medical and surgical groups, CABG prolonged life in patients with double and triple vessel disease and in those completely revascularized.

Adult↗
PubMed1978

Bilateral internal mammary artery mobilization and sternal healing.

Four instances of mediastinal wound infection occurred in 100 patients who underwent bilateral internal mammary artery (IMA) mobilization for coronary bypass. Debridement of 3--5 mm of the sternal edges was performed 6--18 days after the primary operation, and 2 patients required additional, anatomically limited debridement. Wounds were allowed to heal by secondary intention. The wounds of 3 patients healed by 4, 7, and 16 months; they had patent grafts at the postoperative or 1-year catheterization; and they returned to work and are free of angina. The fourth patient died of renal and respiratory failure 3 months after the operation; his wound was healing and had not required additional debridement. These observations indicate that bilateral IMA mobilization does not result in avascularity of the sternum, which required only limited debridement and quickly formed granulation tissue from the periosteum and marrow.

Bacterial Infections↗
PubMed1978

Aortic valve replacement in von Willebrand's disease.

A patient with von Willebrand's disease having aortic valve replacement was managed with cryoprecipitate infusions and monitoring of factor VIII levels. This disorder is associated with low factor VIII levels and abnormal platelet function. There may be no history of bleeding, as the severity of the bleeding tendency varies greatly and fluctuates temporally. The partial thromboplastin time is frequently prolonged, but more detailed studies are necessary to establish a diagnosis (bleeding time, platelet adhesiveness to glass beads and ristocetin, von Willebrand's antigen, ristocetin-von Willebrand's factor, and factor VIII clotting activity). Elevation of factor VIII levels to 50 to 100% of normal allows adequate clotting and is best accomplished with cryoprecipitate or fresh frozen plasma rather than commercial concentrates of factor VIII, whose activity is unpredictable.

Aortic Valve↗
PubMed1978

Atypical mycobacteria and the xenograft valve.

During a 4 month interval, cultures taken at the time of porcine xenograft valve implantation grew a fastidious atypical mycobacterium, Mycobacterium chelonei (Runyon's groups IV), in eight of 20 patients. Initial growth occurred at 2 to 3 weeks in thioglycollate broth only; detailed biochemical and bacteriologic evaluation demonstrates altered catalase activity accounting for its initial slow growth. Only one patient has manifested clinical evidence of infection 5 months after mitral valve replacement. A large pericardial effusion required pericardiectomy. Pericardial tissue and fluid have grown M. chelonei with the same growth characteristics as the initial valve culture. It is recommended that manufacturers of xenograft valve bioprostheses maintain a quarantine of 6 weeks until cultures, smears of culture broth, and microscopic evaluation of aortic wall coupons are negative. Users of these prostheses should keep cultures for a minimum of 3 weeks. Should positive cultures result, antimicrobial therapy should be considered only with clinical evidence of infection.

Animals↗
PubMed1978

Myocardial protection by intermittent perfusion with cardioplegic solution versus intermittent coronary perfusion with cold blood.

The myocardial protection provided by cardioplegic solution using buffered, isosmotic potassium (30 mEq. per liter) was compared with intermittent cold coronary perfusion for 2 hours of aortic cross-clamping in dogs. The cardioplegic solution (Group CS) or cold blood (Group CB) was infused every 15 minutes through a cooling coil to reduce the perfusate temperature to 5 degrees C. Myocardial function after 30 minutes of reperfusion and rewarming was reduced in Group CB with a significant reduction in peak systolic pressure at a left ventricular (LV) balloon volume of 20 ml. and a significant reduction of dp/dt. In contrast, in Group CS, LV function was unchanged from the base-line period. LV compliance also was significantly reduced in Group CB while being unchanged in Group CS. Myocardial extravascular water content, obtained by dessication, was significantly higher in Group CB than in Group CS, which may explain the reduction in compliance. Electron microscopy showed normal ultrastructure in Group CS but extracellular edema in Group CB. Total coronary blood flow showed a sustained increase during reperfusion in both groups. Oxygen consumption rose with rewarming to base-line levels in both groups, whereas lactate and pyruvate consumption was reduced in both groups, particularly Group CB. Cardioplegic solution thus appears to be superior to the intermittent perfusion of cold blood for myocardial protection. The addition of potassium arrest, by markedly reducing myocardial metabolism, improves the protection afforded by cold blood perfusion alone.

Animals↗
PubMed1977

Coronary-subclavian steal.

Of 450 patients undergoing internal mammary artery grafts for coronary artery bypass, proximal subclavian artery stenosis with reversal of flow in the internal mammary and vertebral arteries ("coronary-subclavian steal") subsequently developed in two patients. Carotid-subclavian bypass successfully reestablished antegrade blood flow in the ipsilateral internal mammary and vertebral arteries in both patients. Arch aortography is indicated preoperatively in myocardial revascularization patients in the presence of cerebrovascular symptoms, upper extremity blood pressure gradients, and carotid or subclavian bruits. Should subclavian artery stenosis develop subsequent to myocardial revascularization, carotid-subclavian or acillary-axillary bypass can effectively restore antegrade blood flow and reverse the coronary-subclavian steal.

Adult↗
PubMed1977

Nonsyphilitic coronary ostial stenosis.

From October 1970 to June 1977, a total of 15 patients (12 women) were seen with atherosclerotic coronary ostial stenosis (14 left, one right). All patients had angina and two had aortic valve disease. Additional coronary arterial disease was present in nine. One patient declined surgery and died four months later after myocardial infarction. All patients had coronary bypass grafts and two had aortic valve replacement. One patient with valve replacement and one with preoperative cardiogenic shock died postoperatively. Angina recurred nine months postoperatively in one patient; the others (11) are free of angina. Postoperative catheterization from two weeks to 4.5 years in ten of 12 showed 11 of 13 vein grafts and eight of nine internal mammary artery grafts to be patent. In three patients, only a single left-sided coronary bypass was placed to the left anterior descending artery, because the circumflex branches were too small. Ideally, two left-sided bypass grafts should be placed for left ostial disease.

Adult↗