Human coronary arteries occasionally course intramyocardially--a condition termed Myocardial Bridge. We review the anatomic and pathophysiological basis of the Myocardial Bridge and discuss clinical presentations, prognoses and the current treatment options for this interesting coronary angiographic variant.

Gestational diabetes insipidus is a rare disorder characterized by polyuria and polydipsia due to the inability of the kidneys to concentrate urine. We report two cases of transient gestational diabetes insipidus in which patients responded to intranasal DDAVP (1-deamino-8-D-arginine vasopressin) with greater than 50% increase in urine osmolality and marked reduction in urine output. Intranasal DDAVP was discontinued after their discharge and both patients maintained normal urine output and appropriate urine osmolality. In determining whether diabetes insipidus is present in a patient who is polyuric and hypernatremic, a urine osmolality below that of the plasma suggests the presence of diabetes insipidus. Understanding of the pathophysiology may soon lead to improved methods of prevention, diagnosis and treatment.

BackgroundMarijuana is the commonest illegal drug used in the USA. Legalizing its use as a medical drug is a long-standing debate opposed by the federal government. Marijuana consists of delta-9-tetrahydrocannibol (THC) as an active ingredient. The body has two target receptors for THC in the nervous system: CB(1) and CB(2). CB(1) is located centrally and in some peripheral neurons while CB(2) is located peripherally only. THC medicates its effects on the cardiovascular via the autonomic nervous system Acutely, it causes increase heart rate, precipitating angina in patient with coronary artery disease, atrial fibrillation, supine hypertension, and orthostatic hypotension. Chronic use results in an overstimulation of the parasympathetic nervous system, thus causing sinus bradycardia, and an episode of transient secondary heart block has being reported.Case ReportA 46-year-old black female presented with a syncopal episode lasting for less than a minute. Prior to the episode she felt dizzy and diaphoretic. The dizziness she noted started 1 week ago. The patient was otherwise well, with no history of diabetes, hypertension, or coronary artery disease. There was no medication at home and no recent travel. However, she smoked 2 "bags " of marijuana almost daily for 15 years. Her pulse was 35 b/min; other aspects of her physical examination were normal, except she complained of dizziness lying supine. ECG showed sinus bradycardia with 2:1 AV block. CXR was normal. Since the patient had symptomatic bradycardia a temporary transvenous pacing was put in place. An echo done subsequently was normal except for paradoxical septal movements secondary to pacemaker rhythm. Myocardial infraction was ruled out, and urine toxicology was negative; however, she was not tested for cannabis. Lyme titer and work-up for connective tissue diseases were also negative. Twenty-four hours after temporary wire placement ECG showed complete heart block. The patient was then observed for 72 hours for possible resolution of heart block; however, it persisted, and a permanent pacemaker was inserted.Teaching PointWith the push for medical marijuana use and high frequency among the teenage population any reportable side effects should be taken seriously. The person using marijuana and experiencing persistent dizziness should be encouraged to seek medical attention immediately.

Background:Coronary perforation during percutaneous coronary intervention is a rare but dreaded complication. The risk factors, optimal management, and outcome remain obscure.Objectives:To determine the predisposing factors, optimal management, and preventive strategies. We retrospectively looked at coronary perforations at our catheterization laboratory over the last 10 years. We reviewed patient charts and reports. Two independent operators, in a blinded approach, reviewed all procedural cineangiograms. Data were analyzed by simple statistical methodology.Results:Nine patients were treated conservatively and six patients were treated with prolonged balloon inflation. Six patients were treated with polytetrafluoroethylene (PTFE)-covered stents. One patient required emergency coronary artery bypass graft. No deaths were reported. Subjects with perforations also had a significantly higher total white blood cell count (means 12,134 versus 6,155, 95 % confidence interval [CI], p< 0.0001, n=22), total absolute neutrophil count (means 74.2 % versus 57.1 %, 95 % CI, p<0.0001, n=22), and neutrophil:lymphocyte ratio (means 3.65 versus 1.50, 95% CI, p<0.0001, n=22).Conclusions:Coronary perforations are rare but potentially fatal events. Hypertension, small vessel diameter, high balloon:artery ratio, use of hydrophilic wires, and presence of myocardial bridging appear to be possible risk factors. Most perforations can be treated conservatively or with prolonged balloon inflation using perfusion balloons. Use of PTFE-covered stents could be a life-saving measure in cases of large perforations. Subjects with perforations also had greater systemic inflammation as indicated by elevated white cell counts.

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