Reversibility of High-Grade Atrioventricular Block with Revascularization in Coronary Artery Disease without Infarction: A Literature Review

Ischemia Possibly Associated with High Degree Atrioventricular Block

Conduction restoration in second- and third-degree atrioventricular (AV) block after revascularization in acute coronary syndrome (ACS) setting is well established, however this is not the case in non-ACS setting. We present a case of a patient referred for permanent pacemaker implantation, due to high degree AV block (HAVB), who restored his conduction possibly due to targeted revascularization. Thus, this case sheds insight in the reversibility potential of HAVB after revascularization in non-ACS patients, which although signified in current literature, is still far from being a recommendation, due to lack of robust scientific confirmation.

Dopamine and epinephrine for managing complete atrioventricular block due to nonreperfused acute inferior wall myocardial infarction in a rural hospital: A case report

Inferior wall myocardial infarction occurs in approximately 50% of all myocardial infarctions. The most common conduction disorder of this disease is complete atrioventricular block. Immediate attention must be given to the myocardial infarction patients with conduction block due to the increased mortality rate in these patients. Temporary pacemaker implantation and permanent pacemaker implantation are recommended in complete atrioventricular block cases that do not improve with reperfusion. In this case report, a 64-year-old-female patient came to the emergency department of a rural General Hospital with complaints of epigastric pain, dizziness, nausea, and vomiting for 2 days before admission. She had uncontrolled hypertension without a history of diabetes mellitus, dyslipidemia, smoking, or a family history of heart disease. The electrocardiogram displayed an acute inferior wall myocardial infarction and complete atrioventricular block with escape junctional rhythm with a heart rate of 17 bpm. She was diagnosed with nonreperfused inferior wall myocardial infarction and a complete atrioventricular block. She was successfully treated with only dopamine and epinephrine as the definitive treatment because the patient refused to be referred to a tertiary hospital for percutaneous coronary intervention and pacemaker implantation due to financial reasons. Dopamine and epinephrine may be considered for complete atrioventricular block if transfer to a higher level of care is not feasible and as bridge therapy while waiting for transfer.

Bezold–Jarisch reflex-mediated asystole during dobutamine stress testing: a case report

Background

The Bezold–Jarisch reflex (BJR) is a cardioinhibitory parasympathetic response to activation of ventricular mechanoreceptors, which can result in bradycardia, atrioventricular block, or asystole. This phenomenon has been triggered by acute myocardial ischaemia, intra-arterial nitroglycerine use, natriuretic peptides, and with exceptional rarity, in middle-aged women only, by dobutamine infusion during stress echocardiography.

Case summary

We present the case of a 61-year-old woman who suffered a 5.1-s sinus pause during her 20 μg/kg/min infusion of dobutamine. Recovery was immediate following termination of dobutamine infusion. Concurrent echocardiography was normal, and subsequent cardiac catheterization and electrophysiologic study were normal.

Discussion

This is the fifth documented case of a severe BJR causing asystole during dobutamine infusion, which adds to the accumulating evidence supporting the benign nature of the condition.

High Degree Atrioventricular Block in Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) and Role of Early Revascularization

High degree atrioventricular block (HDAVB) is a rare complication of non-ST-elevation myocardial infarction (NSTEMI) and often requires pacemaker implantation. We describe a case of reversal of HDAVB in a patient with dual atrioventricular node blood supply following coronary revascularization and potential mechanisms of such complications.