1/8. A case of sinus arrest and vagal overactivity during REM sleep.A young man presented with tachycardia and faintness after an episode of influenza. He underwent 24-h heart rate recordings, each of which documented episodes of sinus arrest lasting up to 7.2 seconds. All episodes occurred in the second half of the night and were always accompanied by severe bradycardia. Cardiac function tests failed to disclose anything abnormal. Two polysomnographic recordings demonstrated that the sinus arrests occurred during REM sleep. Power spectral analysis of heart rate variability showed that during the second half of the night there was an abnormal prevalence of vagal activity, particularly during REM sleep stages, presumably responsible for the bradycardia and fall in blood pressure. We speculate that the episodes of sinus arrest are linked to a central mechanism that triggers the autonomic imbalance during REM sleep.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
2/8. neuroleptic malignant syndrome due to promethazine.A 42-year-old man came to our emergency room hyperthermic (oral temperature, 42.4 degrees C), diaphoretic, and delirious. Other findings included labile blood pressure, sinus tachycardia (heart rate, 138/min), tachypnea (respiratory rate 34/min), muscle rigidity, and incontinence. Two days earlier, he had gone to a local clinic with complaints of abdominal pain, nausea, and vomiting. promethazine was prescribed, and this was the patient's only medication on admission. Laboratory studies showed leukocytosis, hypernatremia, metabolic acidosis, elevated creatinine phosphokinase level, elevated transaminase levels, azotemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and myoglobulinuria. The clinical and laboratory findings were characteristic of the neuroleptic malignant syndrome, with promethazine as the offending agent.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
3/8. Alcohol-induced sinus bradycardia and hypotension in patients with syncope.We observed 2 cases of repeated episodes of syncope after alcohol ingestion. Both patients were light drinkers and had carotid sinus hypersensitivity. In both cases, alcohol loading tests repeatedly induced sinus bradycardia and hypotension 1.0-1.5 hours after drinking alcohol. atropine was effective in improving symptoms. A loading test using a glucose solution of equivalent osmolarity and volume was negative. Acute alcohol ingestion usually increases heart rate with variable effects on blood pressure. However, our 2 cases exhibited unusual alcohol-induced sinus bradycardia and hypotension, suggesting a paradoxical increase in parasympathetic activity and/or decrease in sympathetic activity.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
4/8. Persistence and effects of sinus rhythm after fontan procedure for tricuspid atresia.Four patients who had had a Fontan type of procedure for tricuspid atresia 23, 6, 6, and 11 months previously were investigated by ambulatory electrocardiographic recording and simultaneous recording of the jugular venous pressure and echocardiogram of the conduit or pulmonary valve. All had been considerably improved by the operation. In 1 patient episodes of supraventricular tachycardia were recorded but no rhythm disturbance was detected in the other 3. Pulmonary blood flow was shown to be pulsatile and atrial systole is an important factor in this. The conduit valve showed delayed opening and slow closure suggesting that its presence in the pulmonary circuit may be unnecessary.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
5/8. Adverse effects of calcium administration. Report of two cases.calcium chloride, 7 mg/kg, and calcium gluconate, 20 mg/kg, were administered to patients with low or low-normal levels of serum ionized calcium. Both patients had low blood pressure and cardiac index, and did not respond to digitalis, volume expansion, and beta-adrenergic stimulation with dopamine. Administration of calcium rapid increase of serum ionized calcium levels, decrease of serum potassium levels, and development of severe cardiac arrhythmias. Atrioventricular dissociation and further fall of cardiac index and blood pressure were common features of both cases. Administration of exogenous calcium can cause severe complications, even when theoretically indicated.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
6/8. Postural hypotension in a patient with cervical myelopathy due to craniovertebral anomaly.We report a patient with craniovertebral anomaly leading to cervical cord compression who presented with disabling postural hypotension. A 60-year-old electrician presented with progressive weakness of the upper and lower limbs, which had started 7 years previously. He had difficulty in holding urine for the previous year and had blacked out on standing for the past 3 months. He had upper limb wasting and lower limb spasticity, with impaired joint position sense. Autonomic dysfunctions included postural hypotension, absence of sinus arrhythmia, impaired Valsalva ratio, and lack of increase in blood pressure on cold immersion and isometric contraction. Cervical spine radiograph and magnetic resonance imaging revealed atlantoaxial dislocation, klippel-feil syndrome and osteophytes, resulting in cord compression at C2-C4. Partial and selective damage to the descending autonomic fibres may be responsible for postural hypotension in this patient.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
7/8. Treatment of milrinone-associated tachycardia with beta-blockers.PURPOSE: To describe a case of milrinone-associated tachycardia that was successfully treated with two beta-blockers. CLINICAL FEATURES: A 74-yr-old male patient underwent elective abdominal aortic aneurysm repair under combined epidural/general anaesthesia. He had a history of alcohol abuse, controlled hypertension and ischaemic heart disease. Postoperatively, the patient had persistent sinus tachycardia that was initially unsuccessfully treated with metoprolol. Subsequently, the patient's blood pressure and cardiac index decreased with an associated increase in pulmonary artery pressure. Analysis of the ST-segment revealed no evidence of myocardial ischaemia or infarction. These haemodynamic changes were treated with milrinone which exacerbated the baseline tachycardia without adverse blood pressure response. The subsequent administration of beta-blockers (esmolol and metoprolol) was successful in controlling the heart rate response to milrinone without adversely affecting the patient's haemodynamic profile. CONCLUSION: This report demonstrates the efficacy of esmolol and metoprolol for the treatment of milrinone-associated tachycardia, without compromising the haemodynamic effects of milrinone.- - - - - - - - - - ranking = 3keywords = pressure (Clic here for more details about this article) |
8/8. Concealed mechanical bradycardia: an indication for permanent pacemaker implantation.We report a 51-year-old man with severe ischemic cardiomyopathy and heart failure in whom incessant bigeminal ventricular ectopy failed to generate a detectable arterial pressure. This created a mechanical bradycardia despite an adequate electrical heart rate. Dual chamber pacing increased the effective heart rate and allowed discontinuation of an intraaortic balloon pump from which the patient could not otherwise be weaned.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |