When the heart remembers

Cardiac Memory: A Case Report and Review of the Literature

BACKGROUND

A variety of clinical syndromes can cause T-wave inversion (TWI), ranging from life-threatening events to benign conditions. One benign cause of TWI is cardiac memory, which is characterized by the transient inversion of T-waves following abnormal activation of the ventricles, commonly due to intermittent left bundle branch block (LBBB), tachydysrhythmias, electrical pacing, or ventricular pre-excitation.

CASE REPORT

A 72-year-old man presented to the emergency department with chest pain, nausea, vomiting, and headache. Upon arrival, his electrocardiogram (ECG) showed new-onset LBBB with appropriate secondary ST-T wave changes. A subsequent ECG showed disappearance of LBBB and newly inverted T-waves in precordial leads V1-V5, followed by a repeat ECG that again showed LBBB. Serial troponin testing was unremarkable. During hospitalization, echocardiogram and nuclear perfusion stress test were normal. The transient TWIs in this patient were believed to be due to cardiac memory. We performed a literature review and identified 39 published cases of cardiac memory. The most common etiology for cardiac memory was after cardiac pacemaker placement, followed by intermittent LBBB (as was seen in our patient), and post-tachydysrhythmia. Patient ages ranged from 21 to 88 years, with an equal number of cases reported in men and women. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cardiac memory is a poorly understood, rarely observed phenomenon that can occur in the setting of intermittent LBBB. Testing for acute cardiac ischemia and underlying coronary artery disease is still recommended, as the diagnosis of cardiac memory can only be made after negative workup.

[Direct current cardioversion in Abidjan: report of a ten-year practice in Institute of Cardiology of Abidjan, Ivory Coast]

Direct current cardioversion is effective in arrhythmias' termination. Few is known about its use in our practice. This work aims to report its outcomes over a ten-year period in Abidjan.

METHOD

One thousand, three hundred and ninety one charts of arrhythmic patients were reviewed.

RESULTS

Cardioversion was attempted in 102 patients. One hundred and eighty one shocks were delivered with a mean energy of 262, 1 joules. Success occurred in 84 patients (82,3%). Cardioversion failed in 18 patients mostly in atrial fibrillation. Eight serious complications (7,8%) occurred including 1 sinus node dysfunction, 1 pulmonary oedema, 1 metrorrhagia, 2 stroke, 1 pulmonary embolism. Two patients with ventricular tachycardia died of end-stage heart failure and aftermath of a mitral valve surgery.

CONCLUSION

Direct current cardioversion is effective and safe in our practice. Complications are predominantly due to the medical environment such as antiarrhythmic drugs use or clinical conditions.