Implantable cardioverter-defibrillators (ICDs) are an important nonpharmacological option in the treatment of malignant ventricular arrhythmias. Technological advances in current devices permit nonthoracotomy implantation with transvenous lead systems using biphasic shocks. Decreasing device size has resulted in pectoral implantation. Battery longevity is still short in comparison with that of pacemakers. Lead failure rates as well as pacing thresholds are significantly higher than those for cardiac pacing lead systems. Other complications of ICD systems include infection, perforation, and thrombosis. The long-term performance of nonthoracotomy lead systems for ICD devices has now been extensively studied. Sudden death recurrence rates for these systems are less than 2% in 3 years and less than 5% at 5 years. Clinical trials with both monophasic and biphasic systems show a high degree of prevention of sudden death. Comparison of ICD outcome with that of drug therapy in three large retrospective studies and two small prospective randomized trials favors improved survival and sudden death prevention with device therapy. However, these studies need corroboration from large prospective trials. Two large prospective trials, CIDS and the AVID study, are now in progress to address this issue.

Amiodarone↗

PubMedDate not supplied

Reduced beat-to-beat changes of heart rate: an important risk factor after acute myocardial infarction.

The prognostic significance of heart rate variability derived from 24-hour electrocardiographic recordings was investigated in 250 patients with acute myocardial infarction. During a follow-up of 6 months 15 patients experienced a serious arrhythmic event. These patients showed a significantly reduced beat to beat variability (p = 0.006), a slightly reduced 5-min variability (p = 0.04) and no significant differences in the 24-hour variability compared to the patients free of arrhythmic events. Based on Cox proportional hazard analysis, beat to beat variability remained an independent risk factor (p = 0.0036) in addition to the presence or absence of ventricular late potentials (p = 0.0004) and history of previous infarction (p = 0.04).

Aged↗

PubMedDate not supplied

A method for longitudinal microscopic in vivo examinations of morphology, vascularity, and motility in the ovary and the oviduct of the rat.

OBJECTIVE: We developed an in vivo model to enable observation of dynamic changes in morphology, vascularity, and motility of the rat adnexa. METHODS: Immature Sprague-Dawley rats (n = 16) were primed with equine chorionic gonadotrophin (eCG;15 IU) followed by human chorionic gonadotrophin (hCG; 15 IU) 48 hours later to induce ovulation. The experiments were performed during prolonged (up to 12 hours) thiobarbiturate anesthesia. During laparotomy the periovarian bursa was retracted, whereafter the oviductal-ovarian complex was submerged into an organ chamber. Water immersion lenses (4x-40x; final magnification up to 810x) enabled detailed observations that were recorded on Beta-SP videotape. RESULTS: Capillary flow was monitored easily. At the level of the follicle, top blood flow velocity variations (8-10 per minute) were observed in the microvasculature. Ovulations were followed in detail, and oocyte-cumulus complexes were seen later in the oviductal ampulla. Regular contractions in the oviduct were synchronous with the oocyte-cumulus complexes moving back and forth in the oviductal lumen over a distance of about 900 microm. These contractions were more frequent (13-16 per minute) in the postovulatory phase compared with the time before ovulation (9-10 per minute). The oviductal contractions were initiated alternately from either end of the ampulla and were accompanied by a denudation of the oocytes, with a stream of cumulus cells seen moving in an abovarian direction in between contractions. CONCLUSION: High-magnification video recording in vivo was useful for capturing microcirculatory events as well as structural and functional changes of the ovary and the oviduct.

Anesthesia↗

PubMedDate not supplied

Diagnosing depression among new patients in ambulatory training settings.

A research-validated instrument, based upon the Diagnostic and Statistical Manual of Mental Disorders-III, is used as a "gold standard" to compare physician assessments of depression. Twenty-seven of 294 patients (9.2 percent) presenting to three primary care clinics for the first time met clinical criteria for a depressive disorder. Although the 27 depressed patients differed from the nondepressed patients on sociodemographic characteristics, prior service utilization patterns, and clinical variables, only 7 of the 27 were diagnosed as depressed by their primary care physicians. Factors associated with accurate assessment include comment in the patient's chart of a prior psychiatric history. Many depressed patients reporting high levels of dysphoria on a screening instrument had no mood symptoms recorded on their charts.

Adult↗

PubMedDate not supplied

Agnogenic myeloid metaplasia.

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Aged↗