Clinically suspected acute myocarditis with ST-segment elevation, multiorgan dysfunction, and reversible conduction disturbance in an older patient receiving maintenance hemodialysis: A case report

Rationale: ST-segment elevation and marked myocardial injury require urgent exclusion of coronary occlusion. Maintenance hemodialysis adds metabolic, volume, biomarker, and bleeding-related uncertainty. Patient concerns: A 70-year-old woman receiving thrice-weekly hemodialysis developed chest tightness, dyspnea, and upper abdominal pain during dialysis. She returned with recurrent symptoms, severe metabolic acidosis, lactate 21 mmol/L, ST-segment elevation in leads V1–V3, and troponin I that increased from 13,019.45 to >25,000 ng/L. Diagnoses: Coronary angiography showed unobstructed epicardial arteries with Thrombolysis in Myocardial Infarction grade 3 flow. Clinically suspected acute myocarditis remained the leading working diagnosis, but cardiac magnetic resonance imaging and endomyocardial biopsy were not performed and other causes of myocardial injury with non-obstructive coronary arteries could not be definitively excluded. The course was complicated by pulmonary congestion, metabolic and volume instability, hepatic injury, suspected pancreatic involvement, gastrointestinal bleeding, and symptomatic sinus arrest. Interventions: Antithrombotic therapy was reassessed after angiography and withheld when bleeding developed. Early continuous venovenous hemofiltration was performed without circuit anticoagulation, with heparin reintroduced later when clinically appropriate. Continuous renal replacement therapy was used for volume, electrolyte, and acid–base support. A temporary transvenous pacemaker was implanted for telemetry-confirmed sinus arrest with a maximum pause of 8.78 seconds. Outcomes: The maximum R–R interval decreased to 1.97 seconds, permitting pacemaker removal. At approximately 3 months, syncope had not recurred, but persistent atrial fibrillation, New York Heart Association class III symptoms, and an left ventricular ejection fraction of 47% indicated incomplete cardiac recovery. Lessons: In a hemodialysis patient with a ST-elevation myocardial infarction-like presentation and non-obstructive coronary arteries, subsequent management should combine a structured myocardial infarction with non-obstructive coronary arteries differential with explicit diagnostic uncertainty and repeated reassessment of bleeding, metabolic, volume, infectious, and rhythm-related risks.