Atrioventricular block first-degree

Other risk factors for complete heart block were left bundle branch block, first degree atrioventricular block, female gender, volume of alcohol, and number of septal perforators treated (27-29). 

A decision to refer for permanent pacemaker implantation for loss of atrioventricular synchrony due to first degree AV nodal block is challenging. In the setting of normal conduction in the ventricles, the improvement that may be gained by improving atrioventricular synchrony must be weighed against... 

Conduction delays, such as first-degree atrioventricular block... 

A 36-year-old man became hypomanic after lithium was withdrawn because of symptomatic first-degree atrioventricular block (although, how first-degree block could have caused symptoms is unclear) (134). 

Mullins ME. First-degree atrioventricular block in alprazolam overdose reversed by flumazenil. J Pharm Pharmacol 1999 51(3) 367-70. 

Betaxolol is contraindicated in patients with sinus bradycardia, greater than first-degree atrioventricular block, cardiogenic shock, or overt cardiac feilure. It is also contraindicated in patients with hypersensitivity to any of its components. As noted above, severe respiratory reactions have occurred, and the drug must therefore be used with caution in patients with asthma or COPD. Also, because minor changes in heart rate and blood pressure can occur, this agent must be used with caution, or avoided, in patients with a history of cardiac Mlure or heart block. 

The frequency of atrioventricular block has been studied in 600 patients who underwent stress testing with intravenous adenosine 140 micrograms/kg/minute for 6 minutes (29). The patients were young (under 49 years old n = 75), middle-aged (50-65 years n — 214), old (66-75 years n — 195), or very old (over 75 years n — 116). The respective frequencies of first-degree atrioventricular block were 15, 9.3, 14, and 17% (overall... 

The incidence of atrioventricular block has been reported in 600 consecutive patients who underwent stress myocardial perfusion imaging with adenosine (140 micrograms/kg/minute for 6 minutes), and of whom 43 had first-degree heart block before adenosine and 557 had a baseline PR interval less than 200 ms (Table 1) (31). The heart block in all cases was of short duration, was not associated with any specific symptoms, and in no case required specific treatment. The risk of atrioventricular block during adenosine infusion was not increased by the presence of other drugs that might have caused atrioventricular block (digitalis, beta-blockers, diltiazem, verapamil). 

Alkoutami GS, Reeves WC, Movahed A. The safety of adenosine pharmacologic stress testing in patients with first-degree atrioventricular block in the presence and absence of atrioventricular blocking medications. J Nucl Cardiol 1999 6(5) 495-7. 

A 28-year-old African-American man took alprazolam 12 mg. He denied using alcohol, other prescription medications, over-the-counter medications, or illicit drugs. He denied any suicidal intent. He stated that he had taken this large dose because his usual dose of 1-2 mg had failed to relieve his anxiety. He was drowsy and his heart rate was 58/minute. He had marked first-degree atrioventricular block, with a PR interval of 500 ms. 

Atrioventricular block was common (42%) first-degree, 14% second-degree, 17% and complete, 11%). However, first-degree heart block (that is prolongation of the PR interval) without higher degrees of atrioventricular nodal block can occur in the absence of digitalis intoxication. 

Overdose of digoxin in a neonate caused complete atrioventricular block and cardiogenic shock, which were completely reversed within 4 hours after administration of the first dose of antidigoxin antibody a second dose was given 48 hours later, when first-degree atrioventricular block occurred (180). 

Interleukin-10 is a potent anti-inflammatory and immunosuppressive cytokine with beneficial effects expected in a wide range of diseases (1). In healthy volunteers, its adverse effect profile mostly consisted of flu-like symptoms at the highest dose (SEDA-20, 336). First-degree atrioventricular block was noted in a few patients. Due to immunomodulating properties, potential adverse immunological effects, namely an increased risk of infections, autoimmune disorders, or B cell lymphoprolifera-tive disorders, can be anticipated. 

Severe bradypnea and bradycardia requiring external ventricular pacing occurred in a previously asymptomatic 30-year-old woman with a known cardiac conduction defect 85 minutes after a paracervical block with mepivacaine 400 mg (1). First-degree atrioventricular block has been reported (2). 

A 22-year-old woman took an overdose of propafenone (amount unknown) and developed tetany and then generalized convulsions requiring intravenous clonazepam (44). She had a low blood pressure and first-degree atrioventricular block associated with prolonged intraventricular conduction. She was intubated and given intravenous fluids, equimolar sodium lactate, dopamine, and adrenaline. Her cardiac conduction returned to normal. 

A 20-year-old man taking ranitidine 300 mg/day had a brief episode of syncope. The only abnormal finding was first-degree atrioventricular block, which disappeared after withdrawal of ranitidine. Rechallenges on two separate occasions produced recurrence of asymptomatic first-degree atrioventricular block, but cimetidine 400-800 mg/day and famotidine 40-80 mg/day caused no electrocardiographic abnormalities. 

Allegri G, Pellegrini K, Dobrilla G. First-degree atrioventricular block in a young duodenal ulcer patient treated with a standard oral dose of ranitidine. Agents Actions 1988 24(3-4) 237-42. 

Atrioventricular block. There are many types of AV block, such as a first-degree block in which atrial impulses are delayed in the AV conduction to the ventricle. This is shown on the ECG as a prolongation of the PR interval. Digitalis toxicity or excessive K+ levels can be causative. 

Several cases of American hellebore poisoning have been reported in persons who mistook the plant for ramps Allium tricoccum), a type of wild edible leek. Cases typically involved vomiting, slowed heart rate, and reduced blood pressure. Some cases include first- and second-degree atrioventricular block (Crummett et al. 1985 Jaffe et al. 1990 Prince and Stork 2000). 

A patient with bitemporal epilepsy took lacosamide 12 g, gabapentin 56 g, topira-mate 2 g, and zonisamide 2.8 g [104 ]. He became comatose and had repeated generalized tonic-clonic seizures, aspiration, and subsequent pneumonia, hypotension, and first-degree atrioventricular block. He recovered completely after several days of supportive treatment. 

Sinus bradycardia is common, particularly in patients with acromegaly, and first- and second-degree atrioventricular blocks have been associated with octreotide use, but a mechanism has not been identified. The half-life of octreotide is about 90 minutes in healthy individuals and is doubled in cirrhosis. The time course of the bradycardia was inconsistent with the octreotide concentration in plasma but that does not exclude causality. 

After taking rimonabant for 3 weeks a man developed dizziness, palpitation, and exertional dyspnea. He had atrial fibrillation, for which no other causes were found. Rimonabant was withdrawn and 10 days later the rhythm had reverted to sinus rhythm with first-degree atrioventricular block. 

A 76-year-old woman who was taking carvedilol for hypertension and paroxysmal supraventricular dysrhythmias had an attack of transient syncope after taking a single dose of propafenone 600 mg. Her blood pressure was 110/60 mmHg, heart rate 68/minute, and an electrocardiogram showed left bundle branch block and first degree atrioventricular... 

Patane S, Marte F, Di Bella G. Transient syncope, left bundle branch block and first degree atrioventricular block after pill-in-the-pocket administration. Int J Cardiol 2008 126 el9-21. 

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