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Diabetic autonomic neuropathy (DAN) is a serious and common complication of diabetes. Despite its relationship to an increased risk of cardiovascular mortality and its association with multiple symptoms and impairments, the significance of DAN has not been fully appreciated. The reported prevalence of DAN varies widely depending on the cohort studied and the methods of assessment. In randomly selected cohorts of asymptomatic individuals with diabetes, approximately 20% had abnormal cardiovascular autonomic function. DAN frequently coexists with other peripheral neuropathies and other diabetic complications, but DAN may be isolated, frequently preceding the detection of other complications. Major clinical manifestations of DAN include resting tachycardia, exercise intolerance, orthostatic hypotension, constipation, gastroparesis, erectile dysfunction, sudomotor dysfunction, impaired neurovascular function, "brittle diabetes," and hypoglycemic autonomic failure. DAN may affect many organ systems throughout the body (e.g., gastrointestinal [GI], genitourinary, and cardiovascular). GI disturbances (e.g., esophageal enteropathy, gastroparesis, constipation, diarrhea, and fecal incontinence) are common, and any section of the GI tract may be affected. Gastroparesis should be suspected in individuals with erratic glucose control. Upper-GI symptoms should lead to consideration of all possible causes, including autonomic dysfunction. Whereas a radiographic gastric emptying study can definitively establish the diagnosis of gastroparesis, a reasonable approach is to exclude autonomic dysfunction and other known causes of these upper-GI symptoms. Constipation is the most common lower-GI symptom but can alternate with episodes of diarrhea. Diagnostic approaches should rule out autonomic dysfunction and the well-known causes such as neoplasia. Occasionally, anorectal manometry and other specialized tests typically performed by the gastroenterologist may be helpful. DAN is also associated with genitourinary tract disturbances including bladder and/or sexual dysfunction. Evaluation of bladder dysfunction should be performed for individuals with diabetes who have recurrent urinary tract infections, pyelonephritis, incontinence, or a palpable bladder. Specialized assessment of bladder dysfunction will typically be performed by a urologist. In men, DAN may cause loss of penile erection and/or retrograde ejaculation. A complete workup for erectile dysfunction in men should include history (medical and sexual); psychological evaluation; hormone levels; measurement of nocturnal penile tumescence; tests to assess penile, pelvic, and spinal nerve function; cardiovascular autonomic function tests; and measurement of penile and brachial blood pressure. Neurovascular dysfunction resulting from DAN contributes to a wide spectrum of clinical disorders including erectile dysfunction, loss of skin integrity, and abnormal vascular reflexes. Disruption of microvascular skin blood flow and sudomotor function may be among the earliest manifestations of DAN and lead to dry skin, loss of sweating, and the development of fissures and cracks that allow microorganisms to enter. These changes ultimately contribute to the development of ulcers, gangrene, and limb loss. Various aspects of neurovascular function can be evaluated with specialized tests, but generally these have not been well standardized and have limited clinical utility. Cardiovascular autonomic neuropathy (CAN) is the most studied and clinically important form of DAN. Meta-analyses of published data demonstrate that reduced cardiovascular autonomic function as measured by heart rate variability (HRV) is strongly (i.e., relative risk is doubled) associated with an increased risk of silent myocardial ischemia and mortality. The determination of the presence of CAN is usually based on a battery of autonomic function tests rather than just on one test. Proceedings from a consensus conference in 1992 recommended that three tests (R-R variation, Valsalva maneuver, and postural blood pressure testing)or longitudinal testing of the cardiovascular autonomic system. Other forms of autonomic neuropathy can be evaluated with specialized tests, but these are less standardized and less available than commonly used tests of cardiovascular autonomic function, which quantify loss of HRV. Interpretability of serial HRV testing requires accurate, precise, and reproducible procedures that use established physiological maneuvers. The battery of three recommended tests for assessing CAN is readily performed in the average clinic, hospital, or diagnostic center with the use of available technology. Measurement of HRV at the time of diagnosis of type 2 diabetes and within 5 years after diagnosis of type 1 diabetes (unless an individual has symptoms suggestive of autonomic dysfunction earlier) serves to establish a baseline, with which 1-year interval tests can be compared. Regular HRV testing provides early detection and thereby promotes timely diagnostic and therapeutic interventions. HRV testing may also facilitate differential diagnosis and the attribution of symptoms (e.g., erectile dysfunction, dyspepsia, and dizziness) to autonomic dysfunction. Finally, knowledge of early autonomic dysfunction can encourage patient and physician to improve metabolic control and to use therapies such as ACE inhibitors and beta-blockers, proven to be effective for patients with CAN.
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PMID:Diabetic autonomic neuropathy. 1271 21

A 63-year-old man presented with subclavian steal syndrome associated with left internal mammary artery (IMA) bypass graft to a coronary artery. He was admitted with a history of oppressive sensation in the chest, dizziness, and light headedness on exertion for 2 weeks in March 2002. He had undergone myocardial revascularization consisting of a left IMA-to-left anterior descending coronary artery graft in April 1988. His blood pressure was 140/70 mmHg in the right arm and 80/64 mmHg in the left arm. Aortic arch arteriography revealed complete occlusion of the left subclavian artery proximal to the left IMA takeoff and subclavian steal with anterograde flow of the left IMA. Percutaneous angioplasty and stent placement with protection of the left IMA bypass graft using a balloon catheter was successfully performed without complication by cerebral or myocardial ischemia. Complete recanalization of the occluded left subclavian artery and anterograde flow of the left vertebral artery were achieved. His symptoms disappeared and blood pressure in the left arm recovered. This variant of coronary subclavian steal might require protection of the left IMA during angioplasty and stent placement.
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PMID:Percutaneous transluminal angioplasty and stent placement for subclavian steal syndrome with concomitant anterograde flow in the left internal mammary artery graft for coronary artery bypass--case report. 1462 Feb

Dinitrotoluenes (DNTs) are nitroaromatic compounds appearing as pale yellow crystalline solids at room temperature. Dinitrotoluenes exist as a mixture of 2 to 6 isomers, with 2,4-DNT, and 2,6-DNT being the most significant. About 500 persons are estimated to be potentially exposed yearly to 2,4-DNT and 2,6-DNT during the production of munitions and explosives. The main route of human exposure at ammunition facilities is inhalation, but dermal contact and inadvertent ingestion can also be substantial. In factory workers, exposure to DNTs has been linked to many adverse health effects, including cyanosis, vertigo, headache, metallic taste, dyspnea, weakness and lassitude, loss of appetite, nausea, and vomiting. Other symptoms including pain or parasthesia in extremities, abdominal discomfort, tremors, paralysis, chest pain, and unconsciousness have also been reported. The primary targets of DNT toxicity are the hematopoietic system (pallor, cyanosis, anemia, and leukocytosis), the cardiovascular system (ischemic heart disease), the nervous system (muscular weakness, headache, dizziness, nausea, insomnia, and tingling pains in the extremities) and the reproductive system (reduction of sperm counts, alteration of sperm morphology, and aspermatogenesis). An association between DNT exposure and increased risk of hepatocellular carcinomas and subcutaneous tumors in rats, as well as renal tumors in mice, has been established. Epidemiologic studies of DNT toxicity have been limited to small groups of workers who had been occupationally exposed at various ammunitions production facilities. Clearly defining the health effects of DNTs with a high degree of confidence has therefore been difficult because of the multigenic nature of occupational exposure. In an attempt to update the toxicologic profile of the DNTs, we hereby provide a critical review of the environmental and toxicologic pathology of DNTs, with a special emphasis on their potential implications for public health.
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PMID:Environmental toxicology and health effects associated with dinitrotoluene exposure. 1467 15

The records of 38 elderly patients with hip fracture admitted to our hospital between January and December 2002 were retrospectively reviewed to determine the incidence and outcomes of medical complications. The mean age was 84.5 +/- 6.83 years old, 32 women and 6 men. 27 patients (71%) suffered from dementia. Of the 38 patients, 33 (86.8%) had one and more underlying diseases: hypertension 29, cerebrovascular episode 7, congestive heart failure 5, diabetes mellitus 4, gastric ulcer or chronic gastritis 3, ischemic heart disease 4, depression 2. Three patients had a past history of hip fracture. Fourteen patients (37%) developed medical complications after hip fracture, most frequently pneumonia (64%). Other complications were dizziness, nausea, congestive heart failure, choledocholithiasis, and GI tract bleeding. Eight patients who suffered pneumonia cancelled elective surgery. Severity of pneumonia was mild in 2, moderate in 5, and severe in 2. Both cases with severe pneumonia died in hospital. Patients with pneumonia (pneumonia group) were significantly older and had more severe dementia than patients without pneumonia (non-pneumonia group). Although there were no significant differences in physical ability between the two groups before admission, physical ability on discharge was lower in the pneumonia group. The pneumonia group had a significantly longer mean hospital stay than the non-pneumonia group. Our results suggest that the prevention of pneumonia is necessary to improve the outcome of hip fracture.
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PMID:[Effect of pneumonia on clinical course and prognosis after hip fracture]. 1468 54

This is the first known case report of electrocardiographic (ECG) changes suggestive of coronary vasospasm following a centipede envenomation. A 60-year-old man presented to the emergency department (ED) 1 hour after being stung by a 12-cm centipede. He complained of right great toe pain that did not radiate to his leg. The patient had no known ischemic heart disease. He did not describe any exertional symptoms but admitted experiencing weakness. During the ED course, concurrent with obtaining peripheral intravenous access, the patient experienced diaphoresis, dizziness, hypotension, and bradycardia. His ECG showed new ST-T wave changes, which suggested an acute ischemic process. The patient's blood pressure was 89/60 mm Hg, his pulse rate was 47 beats/min, and his respiration rate was 28 breaths/min. In the following hours, ECG findings returned to baseline. His blood pressure improved gradually with fluid resuscitation after approximately 5 hours. Cardiac markers returned to normal in the 13th hour after the event, and the patient underwent exercise stress testing, which was negative. The patient was discharged with cardiology follow-up. Adult patients with centipede envenomation should be closely monitored in anticipation of possible myocardial ischemia due to vasospasm, hypotension, and myocardial toxic effects of the venom. A child receiving the same amount of venom would be potentially at greater risk.
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PMID:Acute coronary ischemia following centipede envenomation: case report and review of the literature. 1522 64

Congenital anomalous origins of the coronary arteries represents a rare but well-described cause of myocardial ischemia and sudden death. Left coronary artery (LCA) arising from the right sinus of Valsalva is a rare congenital coronary anomaly that seems to be commonly associated with sudden death in young trained athletes. The possibility of a coronary artery anomaly should always be considered in young individuals with a history of chest pain or syncope, particularly if the episodes are triggered by exercise. We describe a case of congenital LCA anomaly in an asymptomatic 10-year-old girl with no family history of sudden death; no previous unexplained syncopal episodes or exercise-induced symptoms were reported. She experienced a cardiac arrest while she was resting at school and was not recoverable despite early emergency department admission and intensive prolonged cardiopulmonary resuscitation attempts. Post-mortem pathological findings revealed a single origin from the right sinus of Valsalva for both right and left coronary arteries. The LCA was compressed between the aorta and the pulmonary trunk. Histologic features suggested recent ischemia. Although sudden death can be the first manifestation of this condition, it is important to be particularly aware of prodromic symptoms: exertional dyspnea, chest pain, syncope or dizziness. Recognition during life of this coronary anomaly is mandatory to prevent the risk of sudden death and to plan surgical correction if clinically indicated.
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PMID:Exercise-unrelated sudden death as the first event of anomalous origin of the left coronary artery from the right aortic sinus. 1624 3

A previous article on the safety of amlodipine reviewed data from over 4,000 subjects who participated in clinical trials sponsored by Pfizer Central Research. Once-daily amlodipine was shown to be a well-tolerated treatment of hypertension and myocardial ischemia. Although amlodipine is a potent vasodilator, there was a low incidence of side effects such as headache, flushing, and dizziness. Amlodipine was not associated with adverse effects on hematologic or biochemical safety parameters nor on serum cholesterol or triglyceride levels. Amlodipine did not alter electrical conduction in the heart. Amlodipine had a favorable safety profile in comparative trials vs. beta-blockers. The data base of comparative trials vs. other calcium antagonists was small but the toleration of amlodipine was similar to that of verapamil and diltiazem. No data from comparative trials vs. another calcium antagonist of the dihydropyridine class have been available. This article reviews data from recently completed trials vs. nitrendipine and from trials in which amlodipine was used in combination with other agents. Amlodipine was better tolerated than nitrendipine and had a much lower incidence of side effects usually related to vasodilatation. This difference in side-effect profile was especially marked during the first days of treatment. Amlodipine was well tolerated when used in combination with beta-blockers, diuretics, ACE inhibitors, and nitrates. The gradual onset of action and relatively long half-life of amlodipine are the probable cause for the improved toleration in comparison with other dihydropyridines. Besides the low incidence of trivial side effects, increasing clinical experience with amlodipine provides no evidence that amlodipine is a cause of rare but serious adverse effects. It is concluded that amlodipine is an antihypertensive and anti-ischemic agent that has the combined advantages of a good safety profile with once-daily dosage and a smooth onset and long duration of action.
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PMID:An update on the safety of amlodipine. 1629 14

The authors report the case of a 20-year-old professional soccer player who underwent medical evaluation because of atypical chest discomfort and dizziness precipitated by strenuous effort. The ECG and echocardiogram findings were normal. The young athlete did a treadmill stress test which was negative for myocardial ischemia. His myocardial perfusion imaging and coronary angiography were also normal. Later during the investigation, he underwent treadmill stress echocardiography, during which he developed an intraventricular gradient of over 100 mmHg with end-systolic peak and systolic anterior movement (SAM) of the mitral valve. These echocardiographic findings were not present at rest and disappeared shortly after termination of exercise. The authors discuss the significance of these findings and their potential link to sudden death.
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PMID:Intraventricular gradient during effort in a professional soccer player. Clinical significance. 1646 88

Lyme borreliosis is a tick-borne disease. Cardiac manifestations of the disease are extremely rare. We report a case of Lyme carditis in an otherwise healthy male, who presented to the Accident & Emergency Department with chest pain, dizziness and generally symptoms indicating ischaemic heart disease. This patient, without documented history of Lyme disease, acutely developed third-degree atrioventricular block, which required placement of a transvenous pacemaker and resolved when the patient was administered doxycycline.
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PMID:Lyme carditis: complete atrioventricular dissociation with need for temporary pacing. 1713 68

We present a 46-year-old patient who suffered from cardiac arrest and subsequently underwent placement of an implantable cardioverter defibrillator (ICD). The patient underwent a cardiac catheterization which revealed no significant coronary artery disease. About 1 year later he experienced appropriated and frequent ICD discharges due to monomorphic ventricular tachycardia (VT) with left bundle branch block morphology. His prodromal symptoms were mild dizziness and lightheadedness with no chest pain. Amiodarone, mexiletine, sotalol and dofetilide as well as ablation of two inducible ventricular tachycardias in the electrophysiology studies were unsuccessful in controlling the arrhythmias and ICD discharges. During the last episode, he experienced a mild burning sensation in his chest and was given nitroglycerin 0.4 mg sublingually, which relived his symptoms and aborted the VT. This led to a second cardiac catheterization to investigate whether the VT was being induced by myocardial ischemia. This second coronary angiogram spontaneously revealed significant coronary vasospasm and simultaneously, the patient's cardiac rhythm showed short runs of VT with left bundle branch block morphology. Intracoronary nitroglycerine relieved the coronary vasospasm and terminated the arrhythmia. The patient was treated with isosorbide mononitrate and diltiazem. He remained symptom free with no ICD discharges and no VT in ICD interrogations for more than 2 years. Coronary vasospasm may be silent and with no chest pain which creates a difficult clinical situation particularly if it is associated with ventricular tachycardia and sudden cardiac death. The mechanisms of VT in the setting of coronary vasospasm are not known and increased automaticity, focal discharges, functional unidirectional block with reentry, or a combination of these mechanisms may contribute to inducing the VT during the transient ischemia or rarely in the reperfusion phase. It is important to perform provocative tests to diagnose silent coronary vasospasm in unexplained sudden cardiac arrests.
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PMID:Multiple episodes of ventricular tachycardia induced by silent coronary vasospasm. 1829 82


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