1/55. adenosine-induced cardiac pause for endovascular embolization of cerebral arteriovenous malformations: technical case report.OBJECTIVE: Extremely high flow through arteriovenous malformations (AVMs) may limit the safety and effectiveness of endovascular glue therapy. To achieve a more controlled deposition of glue, we used transient but profound systemic hypotension afforded by an intravenously administered bolus of adenosine to induce rapidly reversible high-degree atrioventricular block. methods AND CASE REPORT: A patient with a large high-flow occipital AVM fed primarily by the posterior cerebral artery underwent n-butyl cyanoacrylate glue embolization. nitroprusside-induced systemic hypotension did not adequately reduce flow through the nidus, as determined by contrast injection in the feeding artery. In a dose-escalation fashion, boluses of adenosine were administered to optimize the dose and verify that there was no flow reversal in the AVM and no other unexpected hemodynamic abnormalities by arterial pressure measurements and transcranial Doppler monitoring of the posterior cerebral artery feeding the AVM. Thereafter, 64 mg of adenosine was rapidly injected as a bolus to provide 10 to 15 seconds of systemic hypotension (approximately 20 mm Hg). Although there were conducted beats and some residual forward flow through the AVM during this time, the mean systemic and feeding artery pressures were roughly similar and remained relatively constant. A slow controlled injection of n-butyl cyanoacrylate glue was then performed, with excellent filling of the nidus. CONCLUSION: adenosine-induced cardiac pause may be a viable method of partial flow arrest in the treatment of cerebral AVMs. Safe, deep, and complete embolization with a permanent agent may increase the likelihood of endovascular therapy's being curative or may further improve the safety of microsurgical resection.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
2/55. Complete atrioventricular block during anesthesia.PURPOSE: To describe a case of asymptomatic first degree atrioventricular block with a bifascicular block that progressed to complete atrioventricular block during anesthesia. This potentially fatal block was successfully treated with transesophageal ventricular pacing. CLINICAL FEATURES: A 67-yr-old man was scheduled for microvascular decompression of the right trigeminal nerve under general anesthesia. His preoperative ECG showed first degree atrioventricular block with complete right bundle branch block and left anterior hemiblock, but he had experienced no cardiovascular symptoms. anesthesia was induced with sevoflurane 5%, and maintained with isoflurane 1.5-2% in oxygen. Fifteen minutes later in the left lateral decubitus position, the systolic arterial blood pressure suddenly decreased from 80 mmHg to 0 mmHg. Then, the ECG abruptly changed from sinus rhythm to complete atrioventricular block. The heart was unresponsive to drug therapy such as atropine 1.3 mg and isoproterenol 0.5 mg, or transcutaneous pacing but transesophageal pacing was successful. CONCLUSION: Asymptomatic first degree atrioventricular block with bifascicular block advanced to complete atrioventricular block during anesthesia. The block was successfully managed with transesophageal pacing.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
3/55. ephedrine-induced complete atrioventricular block with ventricular asystole during rapid concomitant phenytoin infusion: a case report.ephedrine is widely used to elevate blood pressure, however, one should be cautious to use it concomitantly with phenytoin infusion in neurosurgical procedures. A 59-year-old female was admitted for craniotomy with removal of metastatic brain tumor. During operation phenytoin infusion was given to forestall postoperative seizure. hypotension, bradycardia and complete atrioventricular block followed by ventricular asystole suddenly occurred when the patient was given ephedrine to elevate the blood pressure to see the hemostatic effect close to the end of operation. We discontinued the phenytoin infusion and immediately injected 1.5 mg epinephrine. She was successfully resuscitated. We conclude that when phenytoin is used intraoperatively it should be administered by an infusion pump at a rate of less than 25 mg/min and under continuous monitoring of cardiac rhythm, heart rate, and blood pressure. When pressure support is required, the use of a pure alpha-agonist may minimize the risk of adverse reactions in the presence of phenytoin infusion.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
4/55. latex anaphylaxis causing heart block: role of ranitidine.PURPOSE: Treatment with H2 receptor antagonists may cause the heart to be more susceptible to atrioventricular conduction delay when exposed to an overwhelming insult by histamine released during an anaphylactic reaction. We present the case of a woman, pretreated with ranitidine, who developed 3:1 heart block secondary to latex anaphylaxis. We propose that H2 antagonist premedication alone in patients susceptible to anaphylaxis increases their risk of heart block. CLINICAL FEATURES: A 38 yr old obese woman with cervical cancer presented for a radical hysterectomy. Systems review yielded a history of sleep apnea, orthopnea, gastroesophageal reflux, and sciatica. Medications included preoperative ranitidine, 150 mg. There was no history of atopy or allergy. Following general anesthesia induction, at the onset of the surgical procedure the patient developed a severe anaphylactic reaction which was heralded by the onset of 3:1 heart block, with decreases in SpO2, P(ET)CO2 and a decrease in systolic blood pressure to 45 mmHg. This was diagnosed as a possible latex reaction and treated using epinephrine boluses and infusion, fluids, 50 mg diphenhydramine, 50 mg ranitidine and 100 mg hydrocortisone. Following a 48 hr stay in the ICU the patient made an uneventful recovery. Allergy testing with intradermal latex injection and increased plasma tryptase levels confirmed a latex anaphylaxis. CONCLUSION: The use of H2 antagonists alone as a prophylaxis for gastroesophageal reflux may increase the risk of heart block in patients who develop anaphylaxis.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
5/55. Progression of first degree atrioventricular block to second degree Mobitz type I block during spinal anesthesia associated with induced hypertension.A case is presented in which an elderly patient with preexisting first degree atrioventricular (AV) block progressed to second degree Mobitz Type I AV block during spinal anesthesia and associated with hypertension induced by a pure alpha 1 agonist. Second degree AV block caused by increased vagal tone was transient, which resolved as the blood pressure normalized. hypotension due to spinal anesthesia treated with pure alpha 1 agonist can increase AV block in patient with pre-existing first degree heart block.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
6/55. Congestive heart failure treated by the upgrade from VVI to DDD pacing.The case is presented of an elderly woman with normal left ventricular (LV) systolic function and VVI pacing complicated by severe congestive heart failure. The symptoms and findings of congestive heart failure became refractory to medical treatment and resolved with the upgrade of the VVI to a DDD system. Right heart catheterization during VVI pacing showed increased mean pulmonary capillary wedge and right atrial pressures both being normalized under DDD pacing. This case report illustrates the need to consider permanent physiological pacing in elderly patients, even in presence of normal LV systolic function, to ensure AV synchrony when the atrium can be paced, since diastolic LV dysfunction is quite common in these subjects.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
7/55. Atrioventricular dissociation exacerbating posturally-induced syncope.We report a case of an 85-year-old patient with posturally-induced syncope in whom symptoms were reproduced during tilt table testing in conjunction with development of an accelerated junctional rhythm with isorhythmic atrio-ventricular (AV) dissociation. That loss of AV synchrony was crucial to development of hypotension and syncope was demonstrated during electrophysiologic testing in which both an accelerated junctional rhythm and an inducible atypical AV nodal re-entrant tachycardia (AVNRT) were induced. The accelerated junctional rhythm was accompanied by moderate hypotension with the patient in the supine posture, whereas blood pressure was well maintained during atypical AVNRT despite a much faster ventricular rate. Thus, symptomatic hypotension due to AV dissociation, presumably the result of transient autonomic disturbance, may be another manifestation of neurally-mediated syncope.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
8/55. Compound cardiac toxicity of oral erythromycin and verapamil.OBJECTIVE: To report a case of complete atrioventricular (AV) block and QTc prolongation following coadministration of high-dose verapamil and erythromycin. CASE SUMMARY: A 79-year-old white woman was admitted to the hospital due to extreme fatigue and dizziness. On admission, heart rate was 40 beats/min and blood pressure was 80/40 mm Hg. An electrocardiogram showed complete atrioventricular (AV) block, escape rhythm of 50 beats/min, and QTc prolongation 583 msec. This event was attributed to concomitant treatment with verapamil 480 mg/d and erythromycin 2,000 mg/d, which was prescribed one week before admission. DISCUSSiON: This is the first case published describing complete AV block and prolongation of QTc following coadministration of erythromycin and verapamil. CYP3A4 is the main isoenzyme responsible for metabolism of erythromycin and verapamil. Both drugs are potent inhibitors of CYP3A4 and of p-glycoprotein; this may be the basis for the pharmacokinetic interaction between erythromycin and verapamil. In addition to being a woman, our patient had other risk factors for QT prolongation: slow baseline heart rate (probably induced by verapamil), left-ventricular hypertrophy, and possibly ischemic heart disease. CONCLUSIONS: This life-threatening arrhythmia was probably the result of a pharmacokinetic and/or pharmacodynamic interaction of high-dose verapamil and erythromycin.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
9/55. Successful electrical pacing for complete heart block complicating diphtheritic myocarditis.A case of severe diphtheria complicated by myocarditis and neurorespiratory paralysis is reported. The myocarditis manifested with severe conduction disturbances including left bundle-branch block and high grade second degree atrioventricular block leading to Adams-Stokes attacks. Temporary transvenous electrical pacing for.3 days was successful in the management of this complication, but positive pressure ventilation was later required for respiratory paralysis. This case illustrates the potential value of electrical pacing in diphtheritic myocarditis. Sporadic cases of diphtheria still occur and the case fatality ratio remains at 10%, much of which is related to the occurrence of myocarditis.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
10/55. Correction of AV-nodal block in a 27-year-old man with severe obstructive sleep apnea--a case report.A 27-year-old morbidly obese man diagnosed with severe obstructive sleep apnea (OSA) and experiencing significant ventricular asystoles at times exceeding 8 seconds, during polysomnography. The bradyarrhythmias were successfully corrected with the application of a nasal continuous positive airway pressure (CPAP) mask. Follow-up 24-hour ambulatory Holter monitoring without the aid of a nasal CPAP mask and repeat polysomnography with a CPAP mask after several weeks of continuous CPAP therapy during sleep revealed no evidence of ventricular asystole, despite no change in the patient's body mass index. We discuss several mechanisms explaining the findings in this particular patient.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
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