heartbeat represented on paper. cardiac arrhythmias. selective focus on some beats. extra systole ventricular free space to write

angina arrhythmias arrhythmic artery atrial beat block blood bundle cardiac cardio cardiogram cardiology care checkup circulatory clinic closeup diagnose disease ecg ectopic ekg electrical electrocardiogram electrocardiography examine fibrillation graph health heart heartbeat infarct left medical medicine paper print pulse rate result rhythm right science strip tachycardia test ventricular waveform