Identifying PVC Location: Can We Keep It Simple, Please?

Jennifer Busch,

RN, BSN, CEPS, IBHRE Ambassador

jen@charthealthcareacademy.com

How important is it to eliminate or decrease PVC occurrences? Don’t we all have extra beats at some point? Like before a major exam or with the anticipation of having your article accepted into EP lab digest?

I have been asked this same question by healthcare professionals outside of the dark secret world of electrophysiology...

Frequent PVCs have been associated with reversible cardiomyopathy, even in the absence of sustained ventricular arrhythmias or symptoms. According to the 2019 HRS/EHRA/APHRS/LAHRS Expert Consensus Statement on catheter ablation of ventricular arrhythmias, PVC-related cardiomyopathy should be suspected in individuals who present with unexplained cardiomyopathy and frequent unifocal PVCs -- typically >15% of all beats. Interestingly, some patients with similarly high PVC burdens can maintain normal cardiac function, while PVC-induced cardiomyopathy has also been reported in patients with PVC burdens as low as 4 to 5 percent. (1)

The question for readers is this. Will elimination of PVCs using catheter ablation restore “normal” cardiac function? Latchamsetty, R et al. published a retrospective cohort study that included 1,185 patients (55% female; mean age 52 ± 15 years; mean ejection fraction 55 ±10%; mean PVC burden 20 ±13%)  who underwent catheter ablation for idiopathic PVCs at eight centers between 2004 and 2013. They concluded that catheter ablation of frequent PVCs is a low-risk and often effective treatment strategy for eliminating PVCs and associated symptoms. In patients with PVC-induced cardiomyopathy, cardiac function is frequently restored after successful ablation. (2)

How about fun and educational as well? Believe it or not, predicting the area of interest can be fun! Take, for instance, a game we play on my team entitled The ICE Cream Challenge! Whoever guesses the farthest away from the successfully treated area must buy ice cream for the team. ​That is a win-win for everyone, including the patient. And they wonder what we do in dark rooms all day? Play video games and eat ice cream, of course!​

“Let’s simplify a step-by-step approach to PVC localization utilizing the ECG.”

Simply put, “Vectorcardiography (VCG) is a method of recording the magnitude and direction of the electrical forces that are generated by the heart using a continuous series of vectors that form curving lines around a central point.” (3)

Say What?? This definition is as obscure to me as a snake milker. Yes, that is an actual career path if this EP profession doesn’t quite pan out.

STEP 2: RIGHT OR LEFT?

A great starting point to all our combined years of education would be knowing our right from left. It could not be more relevant here. Is this PVC occurring from the right or left ventricle? Or somewhere in between? -- To be covered in the sequel. Close examination of V1 can help ascertain the origin from the right ventricle or the left. ​

STEP 3: HIGH OR LOW?

Is the ectopy occurring from high in the designated ventricle or low? The ventricular tissue extends superiorly and inferiorly within the cardiac axis. The ventricular outflow tracts sit superiorly. The RVOT, or conus arteriosus if you want to impress a date, wraps anteriorly to the LVOT, or aortic vestibule, with the aortic root nestled posterior-septal to the RVOT. Opposite this are the ventricular bodies, extending inferiorly to the apex and base. The leads that assist us in distinguishing those regions are our inferior Leads II, III, and AFV. ​

When you have all these steps and have narrowed in on a zone, it is helpful to mentally view the heart three-dimensionally (or utilize a heart model in the lab). It is difficult to fully grasp PVC location without looking at the heart as multiple structures wrap snuggly to each other.​

Words of Advice: And lastly, let’s not forget what motivates us beyond the cerebral stimulation of electrophysiology. Our patients, of course! Know them before they come into the lab!!! Some of the most revealing details are in the patient's history.

Ice Cream Challenge!

Now just for fun and hopefully ice cream: Here is a practice ECG. Utilize the steps!

Want more information about PVCs?

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References:
 1. Cronin, EM et al. (May 10, 2019). Heart Rhythm Journal. Retrieved from https://doi.org/10.1016/j.hrthm.2019.03.002

2. Latchamsetty, R et al. (Jun-2015). Multicenter outcomes for Catheter Ablation of Idiopathic Premature Complexes. JACC: Clinical Electrophysiology, vol 1(3) 116-123.

3. “Vector.” Merriam-Webster.com. Dictionary, https://www.merriamwebster.com/dictionary/vector). Accessed June 8, 2017.

4.“Vector-Victor” AviationAviation Humor (2022, February 26). Retrieved from aviationhumor.net/we-have-clearance-clarence/ Accessed February 3, 2022.

About the author:

Jennifer Busch, RN, BSN,

CEPS, IBHRE Ambassador is the Sr. Manager of Professional Development for CHART Healthcare Academy.

Jen's contributions include content development, CHART Plus+ project lead for CHI-St. Alexius Hospital & Intermountain Healthcare, and presenter for EP:LIVE course series and mini-courses.

Thank you, Jen, for giving 100%.