Interpretation of cardiac pathophysiology from pressure waveform analysis: the left-sided V wave.

The left-sided V wave is dependent on both left atrial and ventricular pressure/volume filling relationship. The cardiac rhythm and timing of atrial systole also influences the V wave. The morphology of the V wave can reflect the severity of mitral regurgitation with stenosis, but valve areas in this setting may be better assessed by a pressure half-time method. Finally, as queried in our first patient example, V wave alternans is a reflection of left ventricular pressure alternans in a failing heart. Other signs of poor left ventricular function in Figure 1 also included an elevated minimal diastolic pressure and markedly elevated left ventricular end diastolic pressure. Hemodynamic findings of poor left ventricular function will be addressed in detail in a later "Rounds."