PVC
Cardiac cycle – Periventricular – Contraction.
depolarization.
How common are PVC in population.
2-5% number of people had extra beats. Smoe like said 20%
Myocyte action potential is complicated
Why do PVC occur:
Beat occurs little early because:
- Post MI: abnormal automaticity
- Triggered activity – DAD – outflow tract – caffein. EAD – Torsades, drugs, low K.
- Scar mediated – abnormal pattern or pathway of electricity within the heart
PVC come in different ECG patterns
Bigeminy – every other beat
Trigenmy every third beat
Non sustained VT (NSVT)
Couplets
Multifocal
Symptoms of PVC:
Can be entirely asymptomatic
Palpitations irregular pulse
low pulse /BP
Chest discomfort
Shortness of breath
Loss of exercise tolerance
Lightheadedness dizzness
Hemodynamic impact of a PVC:
Can change the peripheral blood pressure – reduced. When measured aortically then it shows a very low blood pressure. This sometimes changes the blood pressure measured heart rate..because low blood pressure does not trigger the automatic blood pressure monitor.
PVC : Ventricular ectopy as a predictor of all cause mortality – pubmed. (pointed to about 30%)
The more you have the worse outcomes.
PVC burden greater than 24% may cause more cardiac issues…(publication : relationship between burden of PVC ….)
PVC diagnostics:
Apple watch, holter monitor, MCOT, smart watches, routine EKG.
Sometimes – adrenaline of exercise brings out the PVC – holter may not show – stress test is a way to find out.
PVC diganosis : is the scar present.
Sometimes scar from inflammation or other causes may show scar inside the heart muscle.
ECG – pathognomic features – SOO (J. Am coll Cardiolo )
Coupling interval can change PVC –
PVC managament:
Beta blockers
Calcium channel blockers
anti arrhythmics – more potent – CAST study)
Ablation:
Targetic injuryt to dystfunction cells inhe heart
Precision attackon disease area…
Small focused equipment:
5 year – VT/PVC ablation totals at SMT – Sarasota as a center.
2025 (133 ablations)
2022 (123 ablations)
ECG based PVC EKG algorithm used the sinus beat for finding out.
Pap PVC: Malignant mitral valve prolapse – can sometimes cause PVC – possibily due to Abnormal Purkinje fibers.
Intracariac echocardigraphy is key during the procusure
Acunav catheter – Siemens-Acuson.
This transforms intracardiac to 3d mapping – fluoroless
Many times of ablators –
RF, pulsed field, alcohol.
Imaging modalities to figure out what the ablaton looks like.
They use a CT scan to find the specific area.
After Ablation: Same day discharge.
In follow up – holter monitoring at 1-2 weeks, short term medication adjustments, AADs, anticoagulants. 1 week to normal sports.
Specific guidelines for PVC management: (Photo)
How do you know where you are at the spot when you in the heart during an ablation:
Looking at things like: timing of the signals, follow the signals from where it is coming from and cauterize it. Sometimes, stimulating the heart with drugs or electricity – it can mimic it…and the software can tell you how close is the simulated one is the actual one.
How do you know – how much is enough. And that comes with experience.
PVC:
Sometimes by lot of coffee, or by alchohol, or by antioxidants from extra virgin olive oil or from dark chocolate can sometimes induce PVC.
PVC – need time to come out.
Premature ventricular complex or contraction or VPD, Ventricular premature depolarization.
IF heart rate is slow – then PVC can come out. When patients are laying down in bed. When exercising, the beats come together right away and at faster heart rate – the T wave and P wave merge, and there is not enough time to come through. When exercise is called overdrive suppression – a few people do have during exercise but it is rare.
Calcium scan – how that may relate to PVC – related to arrythmia formation – it may be related to atherosclerosis in the artery…Coronary artery disease – liable and it is the soft plaque that can rupture and called heart attack.
Sometimes – loss of blood can cause arrythmia and PVC.
Do Pvc affect heart wall thickness – (Afib related heart failure similar) – chambers are a bit dilated but structure of the walls may not change. Afib – can cause really low ejection fraction but can come back soon. If walls thin then its a problem – if there is a scar then sometimes ablation is difficult.
Bulk of people – most of ejection fractions are in 40% … and they get complete normalization after ablation.
Most difficult – asymptomatic with a normal heart with moderate PVC.
A good patient history is very important …
