While obtaining the patient's vital signs, the nurse notes that the patient's heart rate is 136. Which of the following cardiac effects will likely result from the patient's elevated heart rate?
•Ventricular filling occurs during diastole and is the time when the ventricles fill before pumping the blood to the rest of the body. For this reason, there is reduced end-diastolic filling volume, which decreases stroke volume. Despite the faster heart rate, the decreased stroke volume can impair cardiac output and decrease perfusion, even leading to cardiac failure with extreme heart rates and loss of coordinated atrial contraction.
•Ventricular filling time occurs during diastole and is the time when the ventricles fill with blood before pumping the blood to the rest of the body. Ventricular filling time decreases, not increases, with tachycardia.
•Oxygen demand increases, not decreases, as the heart rate increases.
•Stroke volume is the amount of blood pumped by the left ventricle with each cardiac contraction. Tachycardia would decrease, not increase, stroke volume.