✅ Proven Ways to Naturally Stop Heart Palpitations. Stress increases heart rate and blood pressure, straining the heart, but controlled breathing and relaxation techniques (like deep breathing) activate the calming parasympathetic nervous system to help lower heart rate and blood pressure, regulating the heartbeat. Disclaimer: When to Seek Medical Help If you experience a racing heart (palpitations) with dizziness, chest pain, or trouble breathing, seek urgent medical help, as these could signal