Methemoglobinemia due to local anesthesia: a rare cause of cyanosis and chest pain after placement of implantable cardioverter defibrillator.

Although methemoglobinemia is rare in adulthood, it may have fatal consequences if unnoticed. We planned to implant an implantable cardioverter defibrillator ICD in a 50-year-old male patient for primary prevention. Following sterile draping, prilocaine 5 mg/kg (400 mg) was injected subcutaneously for local anesthesia. We injected an additional dose of 200 mg due to pain during subclavian vein puncture. A DDD-R ICD was placed successfully within approximately 40 minutes. The patient complained of sudden chest pain and dyspnea 15 minutes after bed rest and was transferred to the coronary care unit due to cyanosis and deterioration of general status. Physical examination revealed blood pressure of 110/80 mmHg, pulse rate of 110 bpm, and otherwise unremarkable signs. Peripheral oxygen saturation was determined as 83% by pulse oximeter. Possible pneumothorax and cardiac perforation were excluded by emergency chest radiograph and echocardiography. Blood gas analyses was performed to assess for methemoglobinemia, which revealed pH 7.41, pCO2 40 mmHg, oxygen saturation 98.2%, and methemoglobin 7.9% that peaked to 12.3%. Methylene blue (1%) was slowly injected over 10 minutes at a dose of 1 mg/kg. Cyanosis waned and methemoglobin values decreased to 4.1%, 2.1%, and 1.1% at 2, 8, and 16 hours following the administration, respectively. The patient was safely discharged 2 days after implantation of pacemaker. Methemoglobinemia should be considered in cases presenting with cyanosis, non-diagnostic ECG, and a discrepancy in oxygen saturation between pulse oximetry and blood gas analyses.

Mitral annular calcification predicted major cardiovascular events in patients presented with acute coronary syndrome and underwent percutaneous coronary intervention.

Background: Despite the presence of several clinical studies evaluating the association of atherosclerosis and MAC, no data is present regarding the value of MAC in predicting CV adverse events in patients with acute coronary syndrome (ACS).Methods: Prospective, observational cohort study including 314 patients presented with ACS and underwent percutaneous coronary intervention (PCI). MAC was defined by increased echodensity located at the junction of the atrioventricular groove and posterior mitral leaflet on the parasternal long-axis, short-axis, or apical four-chamber view. Patients were followed for a median 25.1 (23.1-26.5) months for any occurrence of major adverse cardiovascular events (MACE).Results: Among 316 patients 46 (14%) had MAC. Seventy (22.1%) patients had MACE during the follow-up. Patients with MACE had higher creatinine, white blood cell count (WBC), C-reactive protein (CRP), peak troponin I, glucose level at admission compared to those without MACE. Age (HR = 1.026, 95% CI = 1.004-1.049; p = .023), myocardial blush grade (HR = 0.637, 95% CI = 0.480-0.846; p = .008), MAC (HR = 2.429, 95% CI = 1.126-5.239; p = .026), and WBC at admission (HR = 1.079, 95% CI = 1.007-1.157; p = .031) were independent predictors for MACE.Conclusion: In patients presented with ACS and underwent PCI, MAC detected by TTE was an independent predictor for MACE during the long-term follow-up.