The hemodynamic consequences of ventricular tachycardias are caused by cardiac and peripheral reactions. As a result, cardiac output and arterial pressure decrease. Even if the decrease is related to the tachycardia rate and left ventricular function, clinical symptoms do not in each case correlate with the degree of hemodynamic compromise. The explanation for this phenomenon is the different cardiac and peripheral reaction of patients to an immediate rise in heart rate. In this regard, it is questionable if pressure monitoring is superior to heart rate monitoring as a sensor for implantable antitachycardia devices.