CARDIACHEARTSoundsS1 Tricuspid & Mitral Valve ClosesS2 Pulmonary & Aortic Valve ClosesS3 Ventricular Filling CompleteS4 Elevated Arterial Pressure (Atrial Kick)WAVE REVIEWIn-DepthP Wave: Atrial depolarizationPR Segment: AV node conductionQRS Complex: Ventricular DepolarizationU Wave: Hypokalemia creates U-waveST Segment: Ventricles depolarizedT Wave: Ventricular repolarization

P Wave: Small upward wave indicating atrial depolarization QRS Complex: initial downward deflection followed by large upright wave, followed by small downward wave; represents ventricular depolarization; masks arterial repolarization; enlarged R portion- enlarged ventricles; enlarged Q portion may indicate probable heart attack T Wave: Dome shaped wave; Indicates ventricular repolarization; flat when insufficient O2; elevated when K levels P-R Interval: Interval from beginning of P wave to R wave; represents conduction time from initial excitation to initial ventricular excitation; Good diagnostic tool; usually normal