Thanks for your question on Healthcare Magic. I can understand your concern. Sexual intercourse is considered as heavy exertion. Palpitations and chest discomfort at climax is suggestive of more about heart related disease. You are already having valvular heart disease. So better to consult cardiologist and get done 2d echo and stress test (trade mill test). You may need valvular replacement if regurgitation is severe. You should avoid sex or heavy duty exercises until this is sorted. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.