Cardiologists say Holiday Heart Syndrome is real and is often triggered by excess alcohol consumption this time of year. It involves cardiac complications that may include atrial fibrillation, which is when the heart is beating irregularly, often rapidly. It can lead to fatigue, shortness of breath, dizziness and in some cases, stroke. Research shows there’s an increase in deaths from heart-related issues between Christmas and New Year’s. Aside from excess alcohol, frigid temperatures and holiday stress are also said to contribute to Holiday Heart Syndrome.