Effect of altering P-R interval on the amplitude of the first heart sound in the anesthetized dog.
D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D006321:Heart / Q000502:physiology; D006326:Heart Auscultation; D006339:Heart Rate; D008943:Mitral Valve / Q000502:physiology; D009119:Muscle Contraction; D009638:Norepinephrine / Q000494:pharmacology; D010138:Pacemaker, Artificial; D016276:Ventricular Function
D009638:Norepinephrine