Electrocardiography of Artificial Electronic Pacemakers

A Pregnant Patient With Narrow QRS Tachycardia

“…Accelerated AV junctional tachycardia is characterized by a gradual mode of onset and offset, regular narrow QRS tachycardia at a ventricular rate of 70 to 130 beats/min, AV dissociation, and occasional retrograde atrial capture presenting with inverted P waves after the QRS complexes. 1,2 The regular ventricular rate can be interrupted by ventricular capture, if AV dissociation is incomplete or an antegrade exit block presents with Wenckebach periodicity. It is commonly observed in patients after cardiac surgery or with digitalis toxicity, hypokalemia, myocarditis, or chronic obstructive lung disease with hypoxia.…”

“…It is most commonly observed after cardiac surgeries or with digitalis toxicity and responds poorly to adenosine. 1,2 Focal ectopic tachycardia is characterized by a regular narrow QRS tachycardia with an atrial and ventricular rate of 100 to 200 beats/min, gradual…”

An Unusual Case of Chest Pain With Wide Complex Arrhythmia—No Stents Needed

“…2 It can also be seen with digitalis toxic effects and is rarely seen in a structurally normal heart. 3,4 It is often self-limiting and does not require treatment with antiarrhythmics, though it must be noted that AIVR and VT have been known to coexist in some clinical settings. 4,5 Because of the slower ventricular rate, fusion and capture complexes are commonly observed in this rhythm.…”

Imaging and Right Ventricular Pacing Lead Position: A Comparison of CT, MRI, and Echocardiography

“…ECGs were analyzed by one author (PAG), and classified as RVOT septal, RVOT nonseptal, apical, or other in accordance with previously used criteria . An apical position was defined as a paced QRS complex with left bundle branch block (LBBB) pattern and superior axis, and RVOT as an LBBB pattern and inferior axis . Among RVOT locations, the lead was classified as RVOT septal if the paced QRS complexes showed no notching in inferior leads, and transition in precordial leads occurred earlier than or at lead V4 (Fig.…”