Device‐guided slow deep breathing in essential hypertension: is cardiac or sympathetic baroreflex sensitivity altered? (1132.7)

Abstract

The influence of device‐guided slow deep breathing (SDB; RESPeRATE□) on arterial baroreflex control of the heart and muscle sympathetic nerve activity (MSNA) in essential hypertension patients remains unclear. To address this, respiratory rate, partial pressure of end‐tidal carbon dioxide (PETCO2), MSNA (microneurography), heart rate (HR) and blood pressure (BP: Finometer) were monitored in 8 hypertensive patients (55±14 years, BMI 28±3 kg/m2, 152±26/71±11 mmHg [systolic/diastolic BP], duration of hypertension 6.4±6.7 years; mean±SD) during 10 min of normal breathing and 10 min of SDB. Cardiac baroreflex sensitivity (sequence technique) and spontaneous arterial baroreflex control of MSNA burst incidence were calculated offline. As expected, SDB decreased respiratory rate (13±4 to 6±1 breath/min, P=0.001), whereas PETCO2 (P=0.22), and mean BP (98±14 to 97±13 mmHg, P=0.11) were unchanged. MSNA burst incidence tended to fall during SDB (median with interquartile range from 46 [34‐56] to 40 [31‐48] bursts per 100 heart beats, P=0.12), however neither cardiac nor sympathetic baroreflex sensitivity were altered (P>0.05). In conclusion, acute device‐guided SDB does not appear to modify cardiac and sympathetic baroreflex sensitivity in patients with essential hypertension.Grant Funding Source: Supported by British Heart Foundation