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Biomedical subjects

N A Stolf

Publications and source records attributed to N A Stolf.

At least 91 records · Page 5Linked to original sources

Stimulated preconditioned skeletal muscle cardiomyoplasty. An effective means of cardiac assist.

Skeletal muscle grafts can be used to mechanically assist the failing heart. In 13 mongrel dogs, latissimus dorsi muscle was preconditioned in situ for 6-8 weeks. Biopsy samples of the muscles were obtained for histochemical analysis. In seven dogs, muscle force and fatigue were compared in conditioned and contralateral unconditioned (controls) muscles. In six dogs, latissimus dorsi cardiomyoplasty was performed in propranolol-induced acute heart failure, and its effects were evaluated by hemodynamic and echocardiographic parameters. Muscle conditioning was responsible for latissimus dorsi transformation to a muscle with predominantly fatigue-resistant type I fibers. Conditioned muscles developed less initial force (-27 +/- 6%) and a longer contraction time (+32 +/- 4%) (p less than 0.05) but did not show fatigue for less than 15 minutes. With synchronous pulse-train stimulation of the muscle flap, cardiac output increased from 1.4 +/- 0.1 (mean +/- SD) to 2.0 +/- 0.2 l/min (p less than 0.05), pulmonary wedge pressure decreased from 16.3 +/- 0.9 to 12.1 +/- 1.4 mm Hg (p less than 0.05), and left ventricular end-diastolic pressure decreased from 18 +/- 2.0 to 13.5 +/- 1.4 mm Hg (p less than 0.05). Echocardiographically derived ejection fraction increased from 39.3 +/- 2.4% to 59.6 +/- 2.9% (p less than 0.05), and fractional shortening increased from 15.4 +/- 1.1% to 26.3 +/- 1.7% (p less than 0.05). Thus, chronic stimulation of skeletal muscles induces fiber transformation and increases resistance to fatigue and force development. Cardiomyoplasty, on the other hand, improves ventricular function in the presence of acute heart failure. This surgical technique represents an alternative method of treatment for advanced myocardial failure.

Animals↗

Bullet in the interventricular septum: report of surgical removal in two cases.

We have had the opportunity of treating two patients who were wounded by gunshot bullets lodged in the interventricular septum (IVS). The first patient was treated by suture of the ventricle in another hospital. He was then directed to our institution where cineangiocardiography and echocardiogram revealed a bullet in the IVS close to the outlet of the left ventricle. The bullet was removed using cardiopulmonary bypass (CPB), through an incision in the right side of the septum. The patient's recovery was satisfactory, and he was asymptomatic in the 18th postoperative month. In January 25th, 1987 we attended another patient hit by a firearm bullet. The X-Ray revealed a bullet in the cardiac area. The patient was submitted to a median sternotomy and an intraoperative echocardiogram was carried out, which showed that the bullet was located in the interventricular septum. With CPB the right atrium was opened up and the bullet was removed from the interventricular septum. The patient's evolution was also satisfactory. These reports demonstrate the importance of complete evaluation of patients with thoracic wounds and the feasibility of diagnosis and surgical removal of bullets from the interventricular septum.

Adolescent↗

Extracranial mycotic aneurysms in infective endocarditis.

Nine of 217 (4.15%) patients with infective endocarditis who were followed from October 1978 to February 1984 had extracranial mycotic aneurysms (MA). Age range of patients was 6-43 years (mean of 24.8 years) and 7 were male. Etiologic agents were Streptococcus viridans (3 cases), Staphylococcus aureus (2 cases), Staphylococcus epidermidis (1 case), and Pseudomonas aeruginosa (1 case). Two patients had negative blood cultures. The MA involved the arteries of the limbs (5 cases), thoracic (3 cases), and abdominal (1 case) arteries. The diagnosis was made by means of physical examination (5 cases), chest roentgenogram (2 cases), ultrasound examination (1 case), and aortography (1 case), at hospital admission (2 cases), early or before antibiotic therapy (2 cases), and from two days to six months after finishing antibiotic therapy (5 cases). All but one patient were operated upon due to MA; bleeding occurred in three cases; surgery was an emergency procedure in one case and performed from 8 to 58 days after the diagnosis of the MA in the others. Signs of infection at surgery were found in one case. In the others, further antibiotic therapy was not administered. There were no limb losses in the peripheral MA. Four patients received surgical treatment for endocarditis. There was one in-hospital death and another one 6 months later due to heart failure.

Adolescent↗