In AF the QRS complex is usually narrow, but it may be wide if aberrant conduction or bundle branch block, left ventricular hypertrophy (LVH) or preexcitation
syndromes such as WPW syndrome.
7 suffered from left ventricular noncompaction and preexcitation
syndrome, and patient no.
Although there is no consensus on the implication of LVFTs in heart diseases, they have been associated with various clinical manifestations in otherwise structurally normal hearts such as functional murmur, preexcitation
, idiopathic ventricular tachycardia, infective endocarditis, cavitary thrombi, regional myocardial hypertrophy, repolarization abnormalities, and genesis of J-waves [2-9].
Individuals (N = 30; 14 males) with average age of 51.9 [+ or -] 14.3 years referred for cardiac electrophysiology study for the suspicion of supraventricular tachycardia with no evidence of ventricular preexcitation
However, SVTs that associate preexcitation
, preexistent bundle branch block or functional aberrant conduction can present as WCTs .
The short PR interval (0.10 seconds), wide QRS complex (0.12 seconds), and delta waves (best seen in leads II, III, aVF, V1, V3-V6), are features of ventricular preexcitation
of the Wolff-ParkinsonWhite type (WPW).
ECG may reveal LV hypertrophy, with preexcitation
 or prolonged  PR interval.
Patients with medical history or clinical or laboratory evidence of serious or unstable disorders, such as coronary artery disease, stroke, or other cerebrovascular events, peripheral vessels diseases diagnosed earlier, heart failure, cardiomyopathy, mitral valve leaflet prolapse syndrome confirmed with echocardiography, preexcitation
syndrome present in electrocardiography (ECG) or in medical history, left bundle branch block, myocardial bridge in medical history, musculoskeletal diseases not allowing the performance of the exercise test, diabetes or other severe systemic or organs diseases, clinical signs of hyperandrogenism, and thyroid disease, were excluded from the study.
This is the essence of "preexcitation
stress theory": to give the body an optimal stimulation in advance, so as to produce adaptive stimulus and start the endogenous protective mechanism to produce a positive regulatory effect.
Inclusion criteria for the control group were age 18-75 years, documented non-AF arrhythmia including one of the following: left atrial tachycardia, paroxysmal supraventricular tachycardia (orthodromic or antidromic), or FBI (fast, broad, and irregular) tachycardia due to a left-sided accessory pathway, preexcitation
on the 12-lead electrocardiogram in an asymptomatic individual in whom the electrophysiology study revealed a left-sided accessory pathway potentially resulting in significant arrhythmia based on its conduction properties, and patient being willing to sign a written informed consent.
To facilitate the planned ablation and to minimize catheter related injury, it is vital to predict the accessory pathway location based on analysis of a 12-lead electrocardiogram demonstrating preexcitation
. Localization of accessory pathways can be anywhere around the antriventricular annuli, left or right sided, or within the septum.
It explains technical aspects and general concepts of electrophysiologic investigation, sinus node function, atrioventricular conduction, intraventricular conduction disturbances, miscellaneous phenomena related to atrioventricular conduction, ectopic rhythms and premature depolarizations, supraventricular tachycardias, atrial flutter and fibrillation, preexcitation
syndromes, recurrent ventricular tachycardia, the evaluation of antiarrhythmic agents, and catheter and surgical ablation in the therapy of arrhythmias.