New arrhythmias
Of the study cohort, 28/390 patients (7.2%) presented or developed new arrhythmias during hospitalization (Table 2). Seven of these 28 patients (25%) had previous documented arrhythmias. There were 3 cases of bradyarrhythmias and 25 tachyarrhythmias. The first bradyarrhythmic patient was a 92-year-old woman who presented with complete AV block associated with a QT of 550 ms and normal electrolytes; the second case was a 51-year-old man who presented with 2:1 AV block with left bundle branch block (LBBB) and developed complete AVB within hours from his admission. Notably, the patient had narrow complex QRS on a clinic visit two years earlier. Both patients did not receive any negative dromotropic drugs; laboratory examinations revealed normal electrolytes, mildly elevated hsTnI (100 and 83 ng/L, respectively; normal values for men women < 35ng/L and 20ng/L, respectively) and elevated CRP (15 and 4.5 mg/dl, respectively; normal value < 0.5 mg/dL). Both had pacemakers implanted during their index hospitalization. A third patient was a 33 year-old man who presented in sinus rhythm without any conduction abnormality and who developed on day 2 transient sinus bradycardia with slow ventricular escape rhythm that resolved within a few hours (Figures 1A and 1B). Notably, the patient’s O2 saturation at that time was 84% and later rose to 90%, his electrolytes were normal and no drugs with negative chronotropic effects were given. Laboratory examinations revealed elevated CRP of 16.58 mg/dl and normal hsTnI (10 ng/L).
There were 25 patients with new tachyarrhythmias: 24 of them had new atrial tachyarrhythmias including 20 with paroxysmal AF. Of the 24 patients with atrial tachyarrhythmias, 7 had a prior history of similar arrhythmias. Notably, during his index hospitalization, one of these patients with new-onset AF also had a documented ventricular fibrillation which was successfully cardioverted (Table 2). This patient did not have prolonged QT and his electrolytes were normal; however, he did have elevated hsTnI of 7049 ng/L and mildly elevated CRP (6.8 mg/dl). Three patients had atrial flutter and 1 patient had an SVT episode (narrow complex regular tachycardia of 195 bpm seen on monitor and terminated with a Valsalva maneuver). Lastly, there was a patient with ventricular tachycardia (VT) storm (Table 1). This patient had an ischemic cardiomyopathy for which he was previously implanted with an ICD. He presented with normal sinus rhythm, however, a week later had respiratory deterioration necessitating mechanical ventilation. He was transferred to ICU where he developed ventricular bigeminy (Figures 1 C and 1D) which deteriorated within an hour to recurrent monomorphic VT episodes. The patient received multiple ICD therapies and his VT’s eventually resolved after intravenous lidocaine and amiodarone. Notably, the patient did not receive ionotropic medications, his QTc was stable around 480 ms and electrolytes were normal, hsTnI increased to 17,578 ng/L and his maximal CRP was 16.58 mg/dL. Importantly, none of the new arrhythmias were discovered by Holter.