Immediate Management of Acquired Third-Degree Heart Block During Hemodialysis

Initial Actions and Hemodynamic Assessment

The American Heart Association recommends stopping dialysis immediately, assessing hemodynamic stability, correcting electrolyte abnormalities, and preparing for transcutaneous pacing while arranging emergent transvenous pacemaker placement, as atropine will likely be ineffective for infranodal third-degree AV block 1
The American College of Cardiology suggests immediately discontinuing hemodialysis to halt ongoing electrolyte shifts and volume changes that are contributing to the dysrhythmogenic state 2
Assess for signs of hemodynamic instability, including altered mental status, hypotension, or signs of shock, which are associated with third-degree heart block during hemodialysis 1
Syncope or presyncope are symptoms that require immediate attention and are associated with third-degree heart block during hemodialysis 3

The National Kidney Foundation recommends immediately obtaining stat electrolytes (potassium, calcium, magnesium) and correcting abnormalities before any other intervention, as dialysis-induced electrolyte fluctuations are the primary trigger for life-threatening dysrhythmias in this population 2
Maintain potassium levels between 3.5-4.5 mmol/L to avoid hyper- and hypokalemia, which can contribute to third-degree heart block during hemodialysis 2
Correct magnesium levels first, as hypokalemia and hypocalcemia are refractory to replacement without adequate magnesium, according to the American Journal of Kidney Diseases 2
Maintain dialysate calcium at 3 mEq/L to avoid hypocalcemia, which can worsen conduction abnormalities, as recommended by the American Journal of Kidney Diseases 4

The American Heart Association advises against relying on atropine for third-degree AV block with wide QRS escape rhythm, as the block is in non-nodal tissue and will not respond to vagolytic agents 1
Atropine may be attempted if the escape rhythm is narrow QRS, but this is a temporizing measure only, and pacing should not be delayed, according to the American Heart Association 1

The American College of Cardiology recommends initiating transcutaneous pacing immediately in hemodynamically unstable patients while preparing for definitive transvenous pacing 1
Transcutaneous pacing is only a bridge to transvenous pacing and requires sedation/analgesia due to pain, as noted by the American Heart Association 1

The National Kidney Foundation recognizes that third-degree heart block during dialysis represents a convergence of multiple risk factors, including left ventricular hypertrophy, underlying coronary artery disease, and electrolyte fluctuations, which increase arrhythmia susceptibility 2
Adjust future dialysis prescriptions to minimize recurrence by using cooler dialysate temperature, slower ultrafiltration rates, and optimizing dialysate potassium and calcium concentrations, as recommended by the American Journal of Kidney Diseases 2, 4

The American Heart Association recommends continuous ECG monitoring until permanent pacemaker placement, as infranodal blocks can progress unpredictably to asystole 3
Monitor electrolytes during and for 4-5 hours post-dialysis in all subsequent sessions, as the dysrhythmogenic window extends well beyond the treatment period, according to the National Kidney Foundation 2