heartbeat rhythm graph on a white background. electric cardiogram.

acute angina attack background beat blood cardiac cardio cardiogram cardiograph cardiology cardiovascular chart chest condition coronary diagnosis disease dizziness ecg ekg electric electrocardiogram electrocardiograph emergency frequency graph graphic health healthcare healthy heart heartbeat heartburn hospital illness infarct intervention life medical medicine monitor myocardial pain palpitation pressure pulse rhythm sick sickness stress stressinduced stroke symptom thrombus vascular wave weakness white