Third degree AV block

Type II second-degree or third-degree AV block absent o Observe... 

Second- or third-degree AV block for diltiazem or verapamil... 

Symptoms of bradyarrhythmias such as second- or third-degree AV block consist of dizziness, fatigue, lightheaded ness, syncope, chest pain (in patients with underlying myocardial ischemia), and shortness of breath and other symptoms of heart failure (in patients with underlying left ventricular dysfunction). 

In patients with second- or third-degree AV block due to underlying correctable disorders (such as electrolyte abnormalities or hypothyroidism), management consists of correcting those disorders. 

On the basis of ECG findings, AV block is usually categorized into three different types (first-, second-, or third-degree AV block). 

Cardiogenic shock preexisting second- or third-degree AV block (if no pacemaker is present) congenital QT prolongation sick sinus syndrome hypersensitivity to disopyramide. 

Heart block If first-degree heart block develops, reduce dosage. If the block persists, drug continuation must depend upon the benefit compared with the risk of higher degrees of heart block. Development of second- or third-degree AV block or unifascicular, bifascicular, or trifascicular block requires discontinuation of therapy, unless ventricular rate is controlled by a ventricular pacemaker. 

IR Individually titrate on the basis of response and tolerance. Initiate with 150 mg every 8 hours (450 mg/day). Dosage may be increased at a minimum of 3 to 4 day intervals to 225 mg every 8 hours (675 mg/day) and, if necessary, to 300 mg every 8 hours (900 mg/day). The safety and efficacy of dosages exceeding 900 mg/day have not been established. In those patients in whom significant widening of the QRS complex or second- or third-degree AV block occurs, consider dose reduction. 

Preexisting second- or third-degree AV block, right bundle branch block when associated with a left hemiblock (bifascicular block), unless a pacemaker is present to sustain the cardiac rhythm if complete heart block occurs recent myocardial infarction (Ml) presence of cardiogenic shock hypersensitivity to the drug. 

If second-or third-degree AV block, or right bundle branch block associated with a left hemiblock occurs, discontinue therapy unless a ventricular pacemaker is in place to ensure an adequate ventricular rate. 

Oral Severe sinus-node dysfunction, causing marked sinus bradycardia second-and third-degree AV block when episodes of bradycardia have caused syncope (except when used in conjunction with a pacemaker). 

Parenteral Marked sinus bradycardia second- and third-degree AV block unless a functioning pacemaker is available cardiogenic shock. 

Patients with decompensated cardiac failure requiring the use of IV inotropic therapy (such patients should first be weaned from IV therapy before initiating carvedilol) bronchial asthma (see Warninas) or related bronchospastic conditions second- or third-degree AV block sick sinus syndrome or severe bradycardia (unless a permanent pacemaker is in place) cardiogenic shock clinically manifest hepatic impairment hypersensitivity to the drug. 

Phenytoin Because of its effect on ventricular automaticity, do not use phenytoin in sinus bradycardia, sino-atrial block, second- and third-degree AV block, or in patients with Adams-Stokes syndrome. 

Bronchial asthma, a history of bronchial asthma, or severe chronic obstructive pulmonary disease sinus bradycardia second- and third-degree AV block overt cardiac failure cardiogenic shock hypersensitivity to any component of the products. 

Contraindications Sick sinus syndrome/second- or third-degree AV block (except in presence of pacemaker), severe hypotension (less than 90mmFIg, systolic), history of serious ventricular arrhythmias, uncompensated cardiac insufficiency, congenital QT interval prolongation, use with other drugs prolonging QT interval... 

CHF, second and third-degree AV block occur rarely. 

Contraindications Bronchial asthma or chronic obstructive pulomonary disease, cardiogenic shock, overt cardiac failure, second and third degree AV block, severe sinus bradycardia, hypersensitivity to dorzolamide, timolol, or any other component of the formulation... 

Contraindications Hypersensitivity to diltiazem Hypotension Sick sinus syndrome Second- or third-degree AV block Acute myocardial infarction and pulmonary congestion Hypersensitivity to Nifedipine Hypersensitivity to isradipine... 

Contraindications are hypotension, cardiogenic shock, marked bradycardia, second or third degree AV-block, Wolff-Parkinson-White (WPW) syndrome, wide complex tachycardia, VT and uncompensated heart failure. 

Bronchial asthma or chronic obstructive pulmonary disease Cardiogenic shock Hypersensitivity to propranolol Overt cardiac failure Second and third degree AV block Severe sinus bradycardia... 

Timolol was withheld and a temporary pacemaker was inserted. Rechallenge with timolol was associated with recnrrence of third-degree AV block. She subseqnently had a permanent dnal chamber pacemaker implanted. 

Sharifi M, Koch JM, Steele RJ, Adler D, PompUi VJ, Sopko J. Third degree AV block due to ophthalmic timilol solution. Int J Cardiol 2001 80(2-3) 257-9. 

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