The below ECG strip shows the irregularly irregular QRS complexes present during atrial fibrillation. Using the first method to determine heart rate would not be accurate because the RR intervals vary significantly. The best way to determine the ventricular heart rate would be to simply count the Q...
A high-fidelity pressure catheter (Model SPC 320, size 2 F, Millar Instruments, Houston, TX, USA) was used to measure pulsatile aortic pressure through the isolated carotid artery on the right side. An electrocardiogram (ECG) of lead II was recorded using a Gould ECG/Biotach amplifier (...