Biomedical subjects

L F Moreira

Publications and source records attributed to L F Moreira.

At least 91 records · Page 5Linked to original sources

PubMed1990

Latissimus dorsi cardiomyoplasty in the treatment of patients with dilated cardiomyopathy.

Stimulated skeletal muscle grafts have been proposed as a means to reinforce ventricular wall in the treatment of severe myocardial failure. Latissimus dorsi cardiomyoplasty was performed in 11 patients with advanced heart failure due to cardiomyopathy who were in New York Heart Association (NYHA) class III or IV despite maximal medical therapy. There were no operative deaths. Eight patients were followed for a mean of 10.8 months. Two patients remain in muscle conditioning protocol. One patient died with latissimus dorsi ischemia and congestive heart failure. Four of the eight patients in long-term follow-up are in NYHA class I, three in class II, and one in class III. At 3 months of follow-up, rest radioisotopic left ventricular ejection fraction increased from 20.5 +/- 3.6% to 26.8 +/- 8.1% (p less than 0.01). Doppler-echocardiography demonstrated that left ventricular segmental wall shortening improved from 11.3 +/- 2.5% to 16.5 +/- 3.9% (p less than 0.01) and left ventricular stroke volume from 22.9 +/- 4.6 to 33.1 +/- 10 ml (p less than 0.01). Cardiopulmonary exercise test showed that maximal oxygen consumption during treadmill test increased from 14.8 +/- 3.7 to 18.2 +/- 3.3 ml/kg.min (p less than 0.05). At 6 months of follow-up, all the above values remained essentially unchanged. Furthermore, nonsustained ventricular tachycardia was abolished without specific medical therapy in four patients. Thus, cardiomyoplasty improves left ventricular function, reverses congestive heart failure, and may improve long-term survival in severe cardiomyopathies.

Adult↗

PubMed1989

Pacing rate increase as cause of syncope in a patient with severe cardiomyopathy.

Hemodynamic deterioration occurs with ventricular pacing rate increase in the presence of severe chagasic cardiomyopathy. Syncope and orthopnea occurred during ventricular pacemaker evaluation when the pacing rate was temporarily increased by magnet application. Cardiac output decreased by 54%, the arterial blood pressure by 38%, and the pulmonary wedge pressure increased by 54%. Such severe myocardial compromise may limit the use of rate modulated pacemakers.

Cardiac Pacing, Artificial↗

PubMed1989

Cardiomyoplasty benefits in experimental myocardial dysfunction.

Beneficial effects of cardiomyoplasty have been documented and the use of this technique in the treatment of dilated cardiomyopathy have been suggested. This study was undertaken to evaluate the effectiveness of stimulated preconditioned latissimus dorsi muscle flaps wrapped around the heart in order to restore ventricular contractility in six adult mongrel dogs with induced myocardial dysfunction by administration of beta blockers and volume loading. Hemodynamic and two-dimensional echocardiographic evaluation were performed 1 week after the surgical procedure and immediately after heart failure induction. With synchronous pulse train electrical stimulation, cardiac output increased from 1.46 +/- 0.13 (+/- SD) to 2.01 +/- 0.16 L/min (p less than 0.01), pulmonary wedge pressure decreased from 15.5 +/- 1.2 to 11.3 +/- 1.6 mmHg (p less than 0.01) and left ventricular end-diastolic pressure from 18.3 +/- 2.4 to 13.5 +/- 1.4 mmHg (p less than 0.04). Echo derived left ventricular ejection fraction increased from 39.3 +/- 2.4 to 59.6 +/- 2.9% (p less than 0.01) and segmental wall shortening from 15.4 +/- 1.2 to 26.3 +/- 1.7% (p less than 0.01), inclusive when the muscle flap was wrapped only around the left ventricle. In conclusion, this study suggests that cardiomyoplasty may be an alternative method of treatment for irreversible cardiomyopathy, including in patients with a great cardiac enlargement in which muscle flap may only be wrapped partially around the heart.

Animals↗

PubMed1989

[Evaluation of aortic insufficiency in aortic dissection. Significance of intraoperative echocardiography on the conservation of the valve. A case report].

A 34-year old man presented with dyspnea and a new murmur of aortic regurgitation (AR). Two months before he had a episode of acute chest pain. The diagnosis of type A chronic aortic dissection was done on the basis of clinical signs and digital angiography. At surgery, intraoperative two-dimensional echocardiography (Iop Echo) showed a large intimal flap prolapsing into the leaflets during diastole causing AR, without primary involvement of the aortic valve. The aorta was transected just above the valve commissures and a 30 mm woven graft was sutured end to end. The false lumen was closed distally and incorporated into the graft-aorta suture line. Valve replacement was not performed. After the surgical procedure, a Iop Echo indicated competence of the aortic valve by means of contrast injection in the aortic root. AR due to the interference of an intimal flap with the aortic leaflets was not yet been reported. To our knowledge, this is the first case of this mechanism and illustrates the potential value of Iop Echo in diagnosis of aortic dissection.

Adult↗

PubMed1989

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↗

PubMed1988

Natural history and treatment of anorectal strictures complicating Crohn's disease.

Forty-four patients seen between 1975 and 1985 with anorectal strictures complicating Crohn's disease have been reviewed to determine the natural history and outcome of surgical treatment. Proctitis was present in 98 per cent, and 93 per cent of patients had sever perianal disease. The site of strictures was rectal in 22, anal in 15 and anorectal in 11 (4 patients had a stricture at 2 sites). Initial treatment was by rectal excision alone in 6, dilatation in 33, and 5 needed no treatment at all. Single dilatation was effective in 15, 8 required two dilatations and in 10 repeated dilatation was necessary. Proctocolectomy was eventually required in 19 patients, 2 have a loop ileostomy and 1 has an ileostomy with a rectal stump in situ. Only 21 remain asymptomatic while 3 continue to need dilatation. Perineal wound healing was delayed in 9 of 19 patients having a proctocolectomy and in 3 the perineal wound has never healed.

Adolescent↗

PubMed1987