INTRODUCTION: This study examines the incidence of vitamin B12 deficiency in three groups of noise-exposed subjects: patients with chronic tinnitus and noise-induced hearing loss (NIHL), patients with NIHL only, and subjects demonstrating normal hearing. MATERIALS AND METHODS: A group of 113 army personnel exposed to military noise was studied. The mean age was 39 years. Chronic tinnitus and NIHL existed in 57 subjects. NIHL alone was observed in 29 subjects, and 27 subjects had normal audiograms. All subjects were queried about noise exposure and dietary habits. Vitamin B12 serum levels were measured. RESULTS: Patients with tinnitus and NIHL exhibited vitamin B12 deficiency in 47% of cases (blood levels < or = 250 pg/mL). This was significantly more (P < .023) compared with NIHL and normal subjects who exhibited vitamin B12 deficiency in 27% and 19%, respectively. CONCLUSION: These observations suggest a relationship between vitamin B12 deficiency and dysfunction of the auditory pathway. Some improvement in tinnitus and associated complaints were observed in 12 patients following vitamin B12 replacement therapy. The authors recommend that routine vitamin B12 serum levels be determined when evaluating patients for chronic tinnitus.

Adult↗

PubMedDate not supplied

Comparison of exercise hemodynamics among nonstented aortic bioprostheses, mechanical valves, and normal native aortic valves.

BACKGROUND: While aortic valve prostheses are known to perform well at rest, few studies have examined them under stress. We compared stress hemodynamics of mechanical valves and nonstented porcine valves in the aortic position to that of normal native aortic valves. METHODS: Dobutamine echocardiography was used to assess mean and peak gradients and effective orifice area index (EOAI) at rest and exercise in patients with the Toronto Stentless Porcine Valve (SPV) (n = 13, mean implant size 25.7 mm), Sorin Bicarbon mechanical valve (SOR) (n = 11, mean implant size 24.5 mm), and patients with normal native aortic valves (NOR) (n = 10). Dobutamine infusion was started at 5 micron/kg per minute, and increased by increments of 5 micron/kg per minute until the target heart rate was achieved or until a maximal dose of 40 micron/kg per minute. RESULTS: At rest and exercise, respectively, cardiac output (L/min) was 5.2 and 10.4 for Toronto SPV; 7.4 and 13.5 for SOR; and 4.6 and 11.2 for NOR. Measured EOAI (cm2) was 1.1+/-0.2 and 1.15+/-0.2 for TORONTO SPV; 1.60+/-0.3 and 1.58+/-0.3 for SOR; and 1.45+/-0.2 and 1.46+/-0.2 for NOR. Mean gradients (mmHg) were 5.48+/-1.1 and 5.83+/-0.9 for TORONTO SPV; 5.26+/-0.8 and 11.3+/-1.8 for SOR; and 1.54+/-0.4 and 2.18+/-0.7 for NOR. Peak gradients (mmHg) were 11.9+/-2.0 and 21.0+/-3.7 for TORONTO SPV; 10.79+/-1.7 and 25.9+/-3.4 for SOR; and 2.38+/-0.9 and 6.1+/-2.3 for NOR. CONCLUSIONS: Although the mechanical group (SOR) had larger measured EOAI, the greater increase in gradients with exercise in this group suggests that the TORONTO SPV is less obstructive to flow.

Aortic Valve↗

PubMedDate not supplied

Mitral valve repair in severe ischemic cardiomyopathy.

BACKGROUND: Patients with ischemic mitral valve insufficiency (MR) and poor left ventricular (LV) function present a high operative risk. Whether to repair or replace these valves is controversial, while some suggest that heart transplant offers a better solution. We investigated our early and late results in this difficult subset of patients. METHODS: Between 1993-1999,115 patients underwent mitral valve repair (MVR) in our department. Twenty-one patients had severe LV dysfunction with ejection fraction < 25%. Mean age was 60 years (range 45-81). Nineteen (90%) were in New York Heart Association (NYHA) Class IV, 7 (33%) underwent emergency surgery, 3 (14%) were in cardiogenic shock, and 2 (10%) were taken to the operating room under cardiopulmonary resuscitation. All underwent coronary artery bypass grafting (CABG) in addition to MVR, with a mean number of grafts 2.9 per patient. RESULTS: There were no early operative deaths. The average stay in intensive care was 5.9 days (range 1-52). There were three late deaths (14%). Follow-up evaluation up to 3 years showed marked improvement in clinical status. Twelve (67%) patients are in NYHA Class I-II, and three (17%) in Class III. Echocardiography revealed good function of the mitral valve in all, although overall LV function did not change significantly. CONCLUSION: (1) MVR in patients with severe ischemic cardiomyopathy can be accomplished with excellent results. (2) There is marked symptomatic improvement in these patients, even though LV function did not seem to be improved. (3) Long-term survival still needs to be defined.

Aged↗

PubMedDate not supplied

Aging and information seeking: patterns in sampling of sucrose solutions.

This study intended to explore age-related strategies of information seeking and decision making, utilizing a content-free task. Better understanding of skills and motives of aged behavior might contribute to more effective intervention for their welfare. Young and old female participants were engaged in detecting the presence of sucrose in solutions of various concentrations. They also reported the number of samplings required for an affirmative or negative decision about each test solution. Compared to young people, the aged sampled more (repetitions) and had a higher detection threshold (intensity of stimulus), indicating higher requirements for information. It was assumed that the sampling curve would be bell-shaped and peak at the point of least certainty about the presence or absence of sucrose (probability of detection = 0.5). Such curve was observed only among the young females when the samplings across concentrations were pooled according to probability of detection. In the aged, the sampling curve was rather monotonic, indicating low utility and interchangeability of information resources. This was attributed to a preset sampling strategy, labeled as over-resourcing, considering the higher baseline and low utility. The implications of such strategy to experimental procedures and every day life were discussed.

Adult↗

PubMedDate not supplied

New technique for infusion of cardioplegic solution in aortic valve incompetence.

Direct coronary cannulation for induction of cardioplegia in patients with aortic valve incompetence may result in ostial stenosis. In order to circumvent this problem, a technique by which the valve was made competent by suturing the cusps together has been recently applied. Thus, an effective aortic cardioplegic infusion could be accomplished.

Aortic Valve↗

PubMedDate not supplied

Retrograde cardioplegia infusion during coronary bypass surgery. Early clinical experience.

Although aortic root cardioplegia infusion has been generally satisfactory, adequate myocardial protection in patients with critical coronary artery disease (CAD) cannot always be achieved by this route. We report our experience with our first 19 consecutive patients, all with exceptionally severe disease in whom the coronary sinus route was utilized for cardioplegia infusion. Eleven had unstable angina, and three had persistent chest pain requiring intensive antianginal therapy right up to time of surgery. Blood cardioplegia was infused via the coronary sinus using a Foley Catheter under a monitored pressure of 30 mmHg. Ischemic time was 83 +/- 27 minutes. Number of vessels bypassed was 4.9 +/- 0.9. Prebypass hemodynamic profile was compared to the profile at 15 and 75 minutes, and at 6, 12 and 24 hours after cessation of bypass, and revealed good preservation of myocardial function: Cardiac index, stroke volume index and pulmonary capillary wedge pressure remained unchanged, systemic vascular resistance decreased by 30%, while changes of lesser magnitude were observed in systemic and pulmonary blood pressure. There was no death and one perioperative myocardial infarction. Myocardial temperature was monitored by needle thermisters and demonstrated homogeneous myocardial cooling in spite of the severity of CAD. Thus, preservation of cardiac function even in patients with critical and extensive CAD can be achieved by coronary sinus infusion of cardioplegia.

Adult↗