The analysis of normal ECG waves of control smokers and non-smokers indicated significantly shortened QRS complex
(P < 0.
Table 1 shows the QT interval, QTc interval, QRS complex
, and PR interval at rest and post-effort.
Heart rate is recalculated and refreshed after each QRS complex
Wide QRS complex
tachycardia (Figure 1a) was determined, and electrical cardioversion was performed several times.
Firstly, QT Pattern signal which will be used for determination of QRS complex
starting and T wave end points was defined as
Thus the QRS complex
overlaps with the muscle noise, P and T overlap with the respiration action .
This therapy has been implanted in about 3,000 patients to date and is the only device therapy available for patients with narrow QRS complex
Care must be taken to examine all leads, looking for the widest QRS complex
Additionally, Mobitz Type II AV block often is accompanied by a widened QRS complex
(Surawicz & Knilans, 2008).
Nowadays, the selection of patients for cardiac resynchronization therapy is made according to electrical and electromechanical dyssynchronization criteria which include the following: electrocardiographic criteria (duration of the PR interval and morphology of the QRS complex
, evaluation of basic rhythm) and echocardiographic parameters to evaluate the left ventricle ejection fraction, size of ventricles, incidence of mitral regurgitation and evaluation of intra--and inter-ventricular asynchrony.
The QRS complex
represents activation of ventricular myocardium, and QRS prolongation may result from a wide range of processes involving the conduction system primarily, the myocardium, or both.
The primary endpoint of the present study was a composite of cardiac death (defined as intractable heart failure, sudden death, or documented arrhythmic death) or new-onset VT (defined as a wide QRS complex
duration of >120 ms, three or more consecutive ventricular complexes, heart rate >100 bpm, and atrioventricular dissociation).