QRS interval


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Related to QRS interval: QT interval

QRS in·ter·val

the duration of the QRS complex in the electrocardiogram.

QRS interval

In the electrocardiogram, the interval that denotes depolarization of the ventricles, between the beginning of the Q wave and the end of the S wave. Its normal duration is 120–200 msec. Shorter durations are found, e.g., in preexcitation. Longer durations are indicative of first-degree heart block.
See also: interval
References in periodicals archive ?
As mentioned above, in the present study barberry extract was associated with increase in QRS interval and decrease in QT interval.
OBJECTIVE: We evaluated the association between a history of arsenic exposure from drinking water and the prolongation of heart rate-corrected QT (QTc), PR, and QRS intervals.
Developmental Changes in the ECG * Gradual decrease in heart rate * Gradual lengthening of the PR interval * Gradual lengthening of the QRS interval * Shift from right to left ventricular dominance Table 2.
Among Non-athletes 2% (1/50) showed increased QRS interval, 2% (1/50) showed decreased QRS interval duration.
Logistic regression analysis was performed in patients with narrow QRS interval. Mitral regurgitant volume >20 ml was determined as the dependent variable and the left atrial diameter, NYHA functional class, E point septal separation, dP/dt, and DYS Inter PAP Sys were included as the independent parameters in the model.
On average, the VDP was significantly reduced by 132.88 mm x msec, and the QRS interval was reduced by 2.95 msec; both indicate a trend away from LVH.
CMS imposed the registry requirement as part of its September decision to pay for implantable cardioverter defibrillators (ICDs) regardless of QRS interval, and to extend coverage to patients with nonischemic cardiomyopathy.
Two factors seemed primarily responsible for limiting the reduction in left ventricular volume by CRT: suboptimal lead placement and a failure by CRT to reduce the QRS interval to less than 120 milliseconds, Dr.
The six high-risk factors are age older than 72 years, NYHA class III-IV status, left ventricular ejection fraction 25% or less, serum creatinine level 1.4 mg/dL or more, QRS interval 140 milliseconds or more, and atrial fibrillation.
They also had to have cardiac dyssynchrony as reflected by a QRS interval of at least 120 msec.
Biventricular pacemakers may be considered in patients with sinus rhythm, a widening QRS interval greater than or equal to 120 milliseconds, and left ventricular dysfunction, and who have persistent, moderately severe class III symptoms despite aggressive treatment with diuretics, ACE inhibitors, and [beta]-blockers.
A prolonged QRS interval has been required for participation in all major CRT trials and is routinely used as a screening criterion for CRT eligibility in clinical practice.