ECGbook.com

Making Medical Education Free for All

ECGbook.com

Making Medical Education Free for All

R Wave Peak Time in Lead II (Pavas Criteria)

Lead II R wave peak time (RWPT) criterion, Pavas criteria

Depolarization in Aberrant SVT
Depolarization in Ventricular Tachycardia
Lead II and Ventricular Tachycardia
Lead II and Ventricular Tachycardia in Clinical Practice

Depolarization in Aberrant SVT

ECG fast depolarization, Lead II R wave peak time (RWPT) criterion, Pavas criteria, supraventricular tachycardia with aberrant conduction

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Wide complex tachycardia, SVT with aberrant conduction due to bundle branch block, RBBB, LBBB

In SVT, the ventricles are depolarized

Through the conduction system rather than through the myocardium

Depolarization through the conduction system is fast

Hence, the beginning of the QRS is steeper

Compared to depolarization through the myocardium in VT

The beginning of the QRS is steep even in SVT with bundle branch block

Because one ventricle is depolarized quickly

Through the intact bundle branch

Depolarization in Ventricular Tachycardia

Lead II R wave peak time (RWPT) criterion, Pavas criteria, ECG Qr, QS, Lead aVR, slow depolarization from ventricular ectopic focus (ventricular tachycardia), Notch in descending limb, broad q(r) wave

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

In ventricular tachycardia (VT), the ventricles are depolarized from a ventricular ectopic focus

Through the myocardium, not through the conduction system

Depolarization through the myocardium is slow

Therefore, the beginning of the QRS is less steep

Compared to depolarization through the conduction system

Notch commonly occurs in a structurally altered heart

The impulse may be "caught" during propagation, e.g., in a scar from a myocardial infarction

From this fact, the following is derived

Diagnosis of VT according to lead II

Lead II and Ventricular Tachycardia

Lead II EKG curve serves as a diagnostic algorithm for wide-complex tachycardia (WCT)
Lead II differentiates wide-complex tachycardia

Differentiates ventricular tachycardia from Aberrant supraventricular tachycardia (SVT)
Does not differentiate preexcitation SVT (e.g., Antidromic AVRT)

It is very simple and quick

Because it only requires evaluating the Lead II EKG

R Wave Peak Time RWPT, VT vs SVT with aberrancy

Wide-Complex Tachycardia

Lead II differentiates the mechanism of wide-complex tachycardia
Differentiates ventricular tachycardia from Aberrant SVT (but not from preexcitation SVT)

The only algorithm that differentiates VT from preexcitation SVT is the Brugada-Stuerer algorithm

Lead II and Ventricular Tachycardia in Clinical Practice

Sensitivity: 93%, Specificity: 99%
In ventricular tachycardia, there is prolonged ventricular depolarization

The initial QRS curve is therefore less steep compared to SVT tachycardia

R Wave Peak Time (RWPT)

Measured from the start of QRS to the peak of QRS
If in Lead II ≥ 50ms, it indicates ventricular tachycardia

DDx wide complex tachycardia, ventricular tachycardia, The lead II R-wave-peak-time 50ms (Pavas criteria)

Wide-Complex Tachycardia

R Wave Peak Time in Lead II ≥ 50ms suggests ventricular tachycardia
If there is no R wave in Lead II

Then the time is measured from the start of QRS to the peak of the Q wave (S wave)
Depends on the direction of the ventricular vector

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, T time - 120ms

Wide-Complex Tachycardia

QRS Duration 0.2s
Heart Rate 160/min.
R Wave Peak Time in Lead II ≥ 50ms - YES

Indicates ventricular tachycardia

R Wave Peak Time is measured

From the start of depolarization (QRS)
To the peak of depolarization (which is almost always the R wave)

Sometimes it is the Q wave (S wave)

Depends on the direction of the ventricular vector

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, R time - 80ms

Wide-Complex Tachycardia

QRS Duration 0.18s
Heart Rate 166/min.
QRS Alternans

Amplitude of QRS complexes regularly changes

R Wave Peak Time in Lead II ≥ 50ms - YES

Indicates ventricular tachycardia

Electrical vectors, re-entry, AVNRT, RBBB

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, R time - 40ms, SVT with RBBB

Wide-Complex Tachycardia

QRS Duration 0.14s
Heart Rate 212/min.
R Wave Peak Time in Lead II ≥ 50ms - NO
Indicates SVT with RBBB (Specifically AVNRT with RBBB)

Typical pattern of RBBB (rsR' - right bunny ear is larger)

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

R Wave Peak Time in Lead II (Pavas Criteria)

Lead II R wave peak time (RWPT) criterion, Pavas criteria

Depolarization in Aberrant SVT
Depolarization in Ventricular Tachycardia
Lead II and Ventricular Tachycardia
Lead II and Ventricular Tachycardia in Clinical Practice

Depolarization in Aberrant SVT

ECG fast depolarization, Lead II R wave peak time (RWPT) criterion, Pavas criteria, supraventricular tachycardia with aberrant conduction

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Wide complex tachycardia, SVT with aberrant conduction due to bundle branch block, RBBB, LBBB

In SVT, the ventricles are depolarized

Through the conduction system rather than through the myocardium

Depolarization through the conduction system is fast

Hence, the beginning of the QRS is steeper

Compared to depolarization through the myocardium in VT

The beginning of the QRS is steep even in SVT with bundle branch block

Because one ventricle is depolarized quickly

Through the intact bundle branch

Depolarization in Ventricular Tachycardia

Lead II R wave peak time (RWPT) criterion, Pavas criteria, ECG Qr, QS, Lead aVR, slow depolarization from ventricular ectopic focus (ventricular tachycardia), Notch in descending limb, broad q(r) wave

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

In ventricular tachycardia (VT), the ventricles are depolarized from a ventricular ectopic focus

Through the myocardium, not through the conduction system

Depolarization through the myocardium is slow

Therefore, the beginning of the QRS is less steep

Compared to depolarization through the conduction system

Notch commonly occurs in a structurally altered heart

The impulse may be "caught" during propagation, e.g., in a scar from a myocardial infarction

From this fact, the following is derived

Diagnosis of VT according to lead II

Lead II and Ventricular Tachycardia

Lead II EKG curve serves as a diagnostic algorithm for wide-complex tachycardia (WCT)
Lead II differentiates wide-complex tachycardia

Differentiates ventricular tachycardia from Aberrant supraventricular tachycardia (SVT)
Does not differentiate preexcitation SVT (e.g., Antidromic AVRT)

It is very simple and quick

Because it only requires evaluating the Lead II EKG

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Wide complex tachycardia

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Wide complex tachycardia, SVT with aberrant conduction due to bundle branch block, RBBB, LBBB

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Wide complex tachycardia, Orthodrome AV, SVT with aberrant conduction due to the Wolff-Parkinson-White (WPW) syndrome

arrows

Lead II R wave peak time (RWPT) criterion, Pavas criteria, Differential Diagnosis (DDx) of Wide-Complex Tachycardia, ventricular tachycardia

Wide-Complex Tachycardia

Lead II differentiates the mechanism of wide-complex tachycardia
Differentiates ventricular tachycardia from Aberrant SVT (but not from preexcitation SVT)

The only algorithm that differentiates VT from preexcitation SVT is the Brugada-Stuerer algorithm

Lead II and Ventricular Tachycardia in Clinical Practice

Sensitivity: 93%, Specificity: 99%
In ventricular tachycardia, there is prolonged ventricular depolarization

The initial QRS curve is therefore less steep compared to SVT tachycardia

R Wave Peak Time (RWPT)

Measured from the start of QRS to the peak of QRS
If in Lead II ≥ 50ms, it indicates ventricular tachycardia

DDx wide complex tachycardia, ventricular tachycardia, The lead II R-wave-peak-time 50ms (Pavas criteria)

Wide-Complex Tachycardia

R Wave Peak Time in Lead II ≥ 50ms suggests ventricular tachycardia
If there is no R wave in Lead II

Then the time is measured from the start of QRS to the peak of the Q wave (S wave)
Depends on the direction of the ventricular vector

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, T time - 120ms

Wide-Complex Tachycardia

QRS Duration 0.2s
Heart Rate 160/min.
R Wave Peak Time in Lead II ≥ 50ms - YES

Indicates ventricular tachycardia

R Wave Peak Time is measured

From the start of depolarization (QRS)
To the peak of depolarization (which is almost always the R wave)

Sometimes it is the Q wave (S wave)

Depends on the direction of the ventricular vector

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, R time - 80ms

Wide-Complex Tachycardia

QRS Duration 0.18s
Heart Rate 166/min.
QRS Alternans

Amplitude of QRS complexes regularly changes

R Wave Peak Time in Lead II ≥ 50ms - YES

Indicates ventricular tachycardia

Lead II R wave peak time (RWPT) criterion, Pavas criteria, initial slow depolarization rate

DDx Wide complex tachycardia, Lead II R wave peak time (RWPT) criterion, Pavas criteria, R time - 40ms, SVT with RBBB

Wide-Complex Tachycardia

QRS Duration 0.14s
Heart Rate 212/min.
R Wave Peak Time in Lead II ≥ 50ms - NO
Indicates SVT with RBBB (Specifically AVNRT with RBBB)

Typical pattern of RBBB (rsR' - right bunny ear is larger)

Electrical vectors, re-entry, AVNRT, RBBB

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers