ABSTRACT
Background: In childhood and adolescence, cardiac arrhythmias are often benign in the absence of congenital heart defects. Nevertheless, life-threatening inherited arrhythmogenic syndromes can become clinically manifest in early childhood. As early symptoms may be similar in both conditions, thorough workup is fundamental to avoid delayed diagnosis and misdiagnosis. Case summary: We present the case of a 26-year-old Caucasian female patient who presented with recurrent non-sustained polymorphic wide complex tachycardia. Structural heart disease was excluded by echocardiography as well as cardiac magnetic resonance imaging. Due to wide complex extrasystoles and couplets with alternating QRS axis occurring at low levels of physical exertion, catecholaminergic polymorphic ventricular tachycardia (CPVT) was suspected and further investigated. Epinephrine testing in combination with an electrophysiological (EP) study with placement of a coronary sinus catheter and subsequent programmed stimulation ruled out CPVT and unmasked wide complex tachycardia as varying aberrant conduction of focal atrial tachycardia (FAT). 3D-navigated mapping of FAT revealed a direct parahisian origin. Due to significantly increased risk of atrio-ventricular (AV) block during ablation, the patient refused ablation and preferred medical antiarrhythmic therapy. Discussion: Given the consequences of both, delayed diagnosis and misdiagnosis of CPVT, thorough workup is fundamental. In case of doubt regarding potential aberrant AV conduction in the context of wide complex tachycardia, an invasive EP study may easily and safely prove or rule out aberrancy.
ABSTRACT
Background: Implantable cardioverter defibrillators (ICDs) are most effective in treating sudden cardiac death. However, accurate diagnostic workup of broad complex tachycardia is crucial to ensure correct indication for ICD treatment and to avoid unnecessary invasive treatment and device-associated morbidity. Case summary: We present a case of atypical atrial flutter with 2:1 atrioventricular (AV) conduction via a left-posterior accessory pathway (AP), leading to the diagnosis of Wolff-Parkinson-White (WPW) syndrome. Upon admission, the 72-year-old patient showed a regular broad complex tachycardia with superior axis and positive concordance in precordial leads, suggestive of either ventricular tachycardia (VT), antidromic AV re-entrant tachycardia (AVRT), or supraventricular tachycardia with antegrade conduction via a left-posterior AP. Interrogation of the two-chamber ICD, which was very likely implanted unjustified in a peripheral clinic before, revealed atrial flutter with 2:1 AV conduction. Remarkably, after the restoration of sinus rhythm, no classic echocardiogram (ECG) criteria for preexcitation syndrome were detected. An invasive electrophysiological study proved the diagnosis of a bidirectionally conducting, left-posterior AP, which was successfully ablated. Discussion: Differential diagnosis of broad complex tachycardia with superior axis and positive concordance of chest leads consists of i) VT with a left ventricular exit at the posterior mitral annulus, ii) antidromic AVRT involving a left-posterior AP, and iii) supraventricular tachycardia predominantly conducted via a left-posterior AP. The absence of classic ECG criteria for preexcitation syndrome does not rule out AP sufficiently, highlighting the importance of minimal surface-ECG preexcitation criteria. In the case of detection of minimal surface-ECG preexcitation criteria, administration of adenosine rules out or proves the existence of an AP noninvasively and cost-effectively.
ABSTRACT
BACKGROUND: Cardiac arrhythmias are a serious complication in patients admitted due to intoxication in suicidal attempts. Upon admission, detailed information about the specific kind of intoxication are frequently missing. The differential diagnoses of electrocardiogram (ECG) changes such as elevation of T-waves, prolongation of the QT-interval or elevation of ST-segments in this special subgroup of patients comprise drug-induced electrolyte disorders or direct toxic effects on cardiac excitation and repolarization. CASE SUMMARY: In this clinical report of a 27-year-old male patient, we present a case of unusual ECG alterations mimicking ST-elevation, high amplitude, biphasic T-waves and prolongation of QT-interval. These changes of surface ECG were induced by ingestion of cylindrical batteries in a suicidal attempt and immediately normalized after removal of batteries by esophagogastroduodenoscopy. DISCUSSION: There is limited literature describing changes in surface ECG in patients having ingested cylindrical batteries. We propose two hypotheses for the occurrence of these changes after ingestion of cylindrical batteries: (i) Cardiac movement within the perturbation field induced by the batteries causes electrical changes on a time scale of the heart rate which are above the threshold of the high pass filter. (ii) The batteries' electrotonic potential affects the membrane currents of cardiac myocytes, not inducing an action potential but generating repolarization abnormalities. Individual factors, such as body constitution and localization of the batteries within the stomach, determine the interindividual characteristics of repolarization abnormalities.
