I believe that 60 Hertz is a harmonic frequency of the human heart beat (~60 beats a minute = 1 beat a second) 60 Hertz interfers with the heart beat. That being said ... according to the pie chart I used in electrical engineering school amps*volts = watts named after James Watt ... the old energy secretary (just kidding) ... Voltage does affect frequency if you apply it to a voltage controlled oscillator (VCO) ... I'm hoping that ol Tookie get many hertz ... maybe even mega hertz
The variations in heart rate are so significant as to render your theory very useless.