Cardiac parasympathetic denervation reduces hypoxic tachycardia, baroreflex sensitivity and heart rate variability in humans

Figures

• 

  Fig. 1. Electroanatomical map depicting left atrium where red dots indicate ablation lesions applied to right superior ganglionated plexus supplying parasympathetic fibres to sinus node (A) and both atria where red dots indicate additional lesions applied to the same plexus from the right atrium (transparent). Green dots show the location of the phrenic nerve, which is spared during ablation (B).

• 

  Fig. 2. Study protocol with examples of the tracings taken from the same study participant before (A) and after (B) parasympathetic cardioneuroablation (PCNA). An asterisk (*) indicates the familiarization period, while the arrow points to a high-dose atropine bolus. Note that, PCNA leads to the suppression of beat-to-beat cardiac parasympathetic activity while blood pressure variability remains unchanged.

• 

  Fig. 3. Changes in resting normoxic heart rate (HR) after parasympathetic cardioneuroablation (PCNA) and atropine (left panel) and determination of the magnitude of parasympathetic cardiac denervation after PCNA (right panel). Data are presented as means ± SD.

• 

  Fig. 4. Changes in the indices of cardiac baroreflex sensitivity following parasympathetic cardioneuroablation (PCNA).

• 

  Fig. 5. Absolute changes in the indices of heart rate variability (left panels) and cardiac baroreflex sensitivity (right panels) as a consequence of parasympathetic neuroablation (PCNA), atropine administration before PCNA (atropine pre-PCNA) and atropine administration after PCNA (atropine post-PCNA). Data are presented as means ± SD.

• 

  Fig. 6. The correlation between relative changes in HR reactivity to hypoxia (hHR slope) and degree of parasympathetic cardiac denervation.