Interview: Gregory M. Marcus, on PVCs, Gastrointestinal Symptoms and Future Research
Published: 18 June 2026
Gregory M. Marcus, MD, MAS is a leading cardiac electrophysiologist, Professor of Medicine at UCSF, and Associate Editor of JAMA. His research focuses on premature ventricular contractions (PVCs), atrial fibrillation, and modifiable lifestyle factors that influence heart rhythm disorders.
We have published his article Evaluation and Management of Premature Ventricular Complexes in our Research & News section.
Recognized as a leading authority on heart rhythm disorders, Dr. Marcus has been featured in numerous national and international media outlets, including CNN, The Wall Street Journal, NPR, Fox News, The Washington Post, and Time Magazine.
In this exclusive interview with Roemheld Syndrome International Foundation IO, Dr. Marcus discusses gastrointestinal triggers, vagal influences, caffeine, and why more research is needed to better understand PVCs.
Key Takeaways
- Dr. Marcus has encountered patients whose PVCs appear related to gastrointestinal symptoms.
- He believes the relationship between the gastrointestinal system and PVCs has not been sufficiently studied.
- Autonomic and vagal influences likely play an important role in some patients.
- More research is needed to identify modifiable PVC triggers and evidence-based preventative strategies.
- Lifestyle factors, including caffeine, remain an important area of ongoing research.
Question 1
In your clinical practice, have you encountered patients whose PVCs appear consistently related to meals, bloating, reflux, or other gastrointestinal symptoms?
Dr. Marcus:
Yes. I can’t say this is the most common trigger that has been identified, but certainly anything that influences autonomic tone — the balance between vagal (parasympathetic) and adrenaline (sympathetic) activity — often seems to be important.
Interestingly, some patients appear to experience more PVCs with increased vagal tone, including during sleep and less during exercise, while others experience more PVCs in association with adrenaline.
In my experience, it tends to be those with the more vagally mediated PVC patterns who report a relationship with gastrointestinal symptoms or GI upset.
Question 2
Do you think the relationship between the gastrointestinal system and ventricular ectopy has been sufficiently studied, or are there important gaps in our understanding?
Dr. Marcus:
This has definitely not been sufficiently studied.
We have conducted studies in patients with atrial fibrillation regarding perceived triggers and have published several papers on the subject, but similar work has not yet been done for PVCs.
One challenge is determining whether a particular trigger genuinely increases the occurrence of PVCs, or whether it simply makes existing PVCs more noticeable to the patient.
My sense is that, in many cases, the trigger truly increases PVC frequency, although enhanced symptom perception can certainly occur as well.
Another important challenge is that PVC mechanisms vary considerably from patient to patient. Some individuals have very high PVC burdens — sometimes 20% of all heartbeats — and in such cases the PVCs may occur frequently regardless of external triggers.
Question 3
Could autonomic or vagal influences plausibly contribute to PVC generation or symptom perception in some patients?
Dr. Marcus:
Yes, almost certainly.
Again, not in every patient, but I am quite convinced that autonomic and vagal influences play a role in many individuals with PVCs.
This is also where caffeine may be relevant.
In our CRAVE trial, which was published after my PVC review article, we found that days when participants were randomly assigned to consume caffeinated coffee were associated with a higher frequency of PVCs compared with days when they avoided coffee.
We are currently pursuing additional research to explore this relationship further and to determine whether longer-term caffeine exposure influences PVC frequency.
Question 4
Many patients report that their palpitations worsen after eating but have otherwise normal cardiac investigations. How would you generally approach such cases?
Dr. Marcus:
I would obtain a continuously recording ECG monitor and ask the patient to activate the symptom marker whenever symptoms occur.
The goal is to correlate the patient’s symptoms with their actual heart rhythm.
In some cases, patients can experience a sensation of palpitations while maintaining a completely normal rhythm, although this is relatively uncommon.
Question 5
Looking ahead, what areas of PVC research do you believe deserve greater attention?
Dr. Marcus:
Identifying modifiable triggers for PVCs is near the top of my list.
We need a better understanding of the exposures, behaviours, and lifestyle factors that may meaningfully influence PVC frequency.
In atrial fibrillation, sufficient evidence now exists to support guideline recommendations regarding lifestyle modifications that can reduce disease burden.
We are not yet at that stage for PVCs.
Generating the evidence necessary to provide clear, evidence-based recommendations for PVC patients remains an important research priority.
Help Advance PVC Research
Following this interview, Dr. Gregory Marcus expressed a particular interest in hearing more about how PVCs affect patients in daily life and what triggers may influence symptom burden. If you experience PVCs, palpitations, skipped beats, or other heart rhythm symptoms, we would love to hear your story.
Questions of particular interest include:
How do PVCs affect your quality of life?Have they changed your behaviour, exercise habits, diet, work, travel, or social activities?Have you identified any triggers, such as meals, bloating, reflux, caffeine, alcohol, stress, or sleep?What has helped, and what has not?
Selected stories and anonymous summaries may help inform future research into PVCs and potential preventative strategies.
To share your experience, please contact us by email, or use the Patient Story Form on the homepage.
Editor’s Note
Dr. Marcus’s comments do not constitute an endorsement of Roemheld Syndrome as a formal diagnosis. However, his observations are notable because they come from one of the world’s leading cardiac electrophysiologists and researchers in heart rhythm disorders.
Several themes emerge from this interview:
- Gastrointestinal symptoms and PVCs may be linked in some patients.
- Autonomic and vagal influences likely contribute to PVC generation or symptom perception in at least a subset of individuals.
- The relationship between gastrointestinal disorders and ventricular ectopy remains insufficiently studied.
- More research is needed to determine which lifestyle and environmental factors can reliably influence PVC frequency.
For patients who experience palpitations, skipped beats, or PVCs in association with meals, bloating, reflux, or other digestive symptoms, Dr. Marcus’s comments highlight an important reality: these observations deserve further scientific investigation rather than automatic dismissal.
Published with the kind permission of Gregory M. Marcus, MD, MAS.