July 1, 1991Pacing and Clinical Electrophysiology
Complete Atrioventricular Block Following Mediastinal Irradiation: A Report of Six Cases
Population
6 patients with episodic complete infranodal atrioventricular block requiring permanent pacemaker…
Design
Case_series
Follow-up
Mean delay 12 years after irradiation (range 10-18)
Authors
Discussion
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Implication
Delayed infranodal AVB may be radiation-related when pericardial disease is present; leaves open prospective validation of proposed diagnostic criteria.
Key Points
- Characterize delayed complete infranodal atrioventricular block following mediastinal irradiation and establish clinical criteria to confirm radiation etiology.
- Evaluated 6 clinical cases presenting with episodic complete infranodal atrioventricular block requiring permanent pacemaker implantation after mediastinal radiotherapy.
- Assessed prior radiation history (mean dose 5,200 rads, range 4,000–6,500), interval electrocardiograms, Holter monitoring, invasive electrophysiological studies (N=5), and associated pericardial or mediastinal pathology.
- Infranodal block developed after a mean latency of 12 years (range 10–18 years) post-irradiation, presenting at a mean age of 48 years (range 25–60 years).
- All 6 patients exhibited baseline conduction abnormalities (3 left bundle branch block, 2 right bundle branch block, 1 alternating block) and concurrent pericardial disease (4 with pericardial constriction).
- Proposed diagnostic criteria include radiation dose >4,000 rads, latency ≥10 years, abnormal baseline interval tracings, pericardial involvement, and associated mediastinal radiation lesions.
Structured PICO
P
Population
6 patients with episodic complete infranodal atrioventricular block (AVB) requiring permanent pacemaker implantation following mediastinal irradiation, mean age 48 years (range 25-60).
I
Intervention
Mediastinal irradiation (mean dose 5,200 rads, range 4,000-6,500).
O
Outcome
Complete atrioventricular block (AVB)safety
High-dose mediastinal irradiation can lead to delayed complete infranodal atrioventricular block requiring pacemaker implantation, often associated with pericardial and mediastinal lesions.
Cite This Study
Slama et al. (1991) studied this question.