EKG finding of ventricular premature beats -a) Fusion beatb) Narrow QRS complexc) AV Dissociationd) Wide QRS complexe) Capture beat
**Question:** EKG finding of ventricular premature beats - a) Fusion beat, b) Narrow QRS complex, c) AV dissociation, d) Wide QRS complex, e) Capture beat
**Core Concept:** Ventricular premature beats (VPBs) are abnormal electrical events that occur before the normal ventricles' depolarization and repolarization. These can lead to various EKG findings, including fusion beats, narrow QRS complex, AV dissociation, wide QRS complex, and capture beats.
**Why the Correct Answer is Right:**
1. **a) Fusion beat:** When a premature ventricular contraction (PVC) occurs during a ventricles' depolarization, the PVC and the normal depolarization overlap, resulting in a fusion beat. This fusion causes a normal QRS complex with the characteristics of both the PVC and the normal ventricle depolarization.
2. **b) Narrow QRS complex:** A normal ventricular depolarization has a narrow QRS complex. If a PVC occurs before a normal ventricular depolarization, the QRS complex will appear narrow because the premature contraction is not as extensive as the normal ventricular depolarization.
3. **c) AV dissociation:** AV dissociation occurs when the PVC occurs during the atrioventricular (AV) node conduction, causing an asynchronous ventricular contraction. This is not a correct answer for VPBs' EKG findings.
4. **d) Wide QRS complex:** A premature ventricular contraction occurring during repolarization (the early phase of ventricular repolarization) results in a wide QRS complex.
5. **e) Capture beat:** A capture beat occurs when the PVC is conducted through the AV node and reaches the ventricles. It would not be a correct answer for EKG findings of VPBs.
**Why Each Wrong Answer is Incorrect:**
1. **AV dissociation:** As mentioned earlier, AV dissociation occurs when the PVC occurs during the atrioventricular node conduction. This is not an EKG finding related to VPBs.
2. **Capture beat:** A capture beat represents a normal ventricular contraction triggered by the premature ventricular contraction. This is not an EKG finding associated with VPBs.
3. **AV dissociation:** This answer is incorrect, as it refers to a different phenomenon than the EKG finding of VPBs.
4. **Wide QRS complex:** While a wide QRS complex may occur in some cases of VPBs, it is not a definitive EKG finding for VPBs.
5. **Narrow QRS complex:** A narrow QRS complex is found in VPBs during the depolarization phase.
**Core Concept:** The EKG findings of VPBs include fusion beats, narrow QRS complex, and wide QRS complex. The correct answer is **d) Wide QRS complex** because it represents VPBs occurring during the repolarization phase.
**Why Each Wrong Answer is Incorrect:**
1. **AV dissociation:** This refers to a different phenomenon than the EKG finding of VPBs.
2. **Fusion beat