Cardiovagal and sympathetic baroreflex regulation in heart failure

Osszefoglalo. Bevezetes: Az arterias baroreflex-erzekenysegi (BRS-) indexek egysegnyi nyomasvaltozasra adott elettani valaszokat irnak le. Az RR-intervallum gyors valaszait a cardiovagalis BRS-indexekkel, a vasomotorvalaszokat az izom szimpatikus idegi aktivitas (MSNA) valaszain alapulo szimpatikus-BRS-indexekkel jellemezzuk. Szivelegtelensegben korosan csokkent ertekeik kedvezőtlen kimenetelt jeleznek. Betegek es modszerek: A BRS-indexek meghatarozhatosagat 52, szivelegtelensegben szenvedő betegben (kor: 59 ± 10 ev; EF: 37 ± 11%) es 11, kor szerint illesztett egeszseges onkentesben vizsgaltuk. EKG- es vernyomasfelvetelekből harom cardiovagalis BRS-indexet szamitottunk; a novekvő, illetve csokkenő spontan szekvenciak modszeren alapulo up-BRS-t es down-BRS-t, tovabba az alacsony frekvenciatartomany-beli 'cross-spectralis ' indexet, az LF-alfat. Egy periferias ideg (nervus peroneus) perkutan punkciojaval detektaltuk az MSNA szimpatikus csucs incidenciajat (csucs/100 szivciklus), s ezt korrelaltattuk a diastoles nyomas 3 Hgmm savokba rendezett ertekeivel. Igy nyertuk a szimpatikus BRS jellemzőit, a BRSSY-incidencia-ertekeket. Eredmenyek: Az up- es down-BRS-szekvenciak csak a betegek 19%-aban voltak meghatarozhatok, az LF-alfa a 69%-ukban. Azok, akiknel cardiovagalis BRS nem volt meghatarozhato, szignifikansan csokkent RR-intervallum-ingadozast es magasabb NT-proBNP-ertekeket mutattak. A meghatarozhato cardiovagalis BRS-indexek nem kulonitettek el a betegeket es a kontrollszemelyeket. A BRSSY-incidencia-ertek 58%-ban allt rendelkezesre, s csakugy, mint maga a "csucs" incidencia, jol elkulonitette a betegeket es az onkenteseket. A hianyzo baroreflexertek a magas "csucs" incidenciaval allt osszefuggesben. Kovetkeztetes: A cardiovagalis BRS-ertekek csak korlatozottan alkalmasak egeszseges onkentesek es szivelegtelen betegek elkulonitesere, a meghatarozhatatlan ertekek sulyosabb betegsegre utalnak. A BRSSY-incidencia elkuloniti az egeszseges es a beteg csoportokat; a hianyzo ertek a fokozott szimpatikus aktivitassal all osszefuggesben. Orv Hetil. 2021; 162(3): 91-98. SUMMARY INTRODUCTION Arterial baroreflex sensitivity (BRS) is characterized by the magnitude of physiological responses to arterial pressure changes. Rapid RR interval responses are quantified by cardiovagal BRS parameters, sympathetic responses could be assessed by changes in muscle sympathetic nerve activity (MSNA). Abnormal indices in heart failure are associated with poor outcome. PATIENTS AND METHODS 52, heart failure patients (age 59 ± 10 years, EF 37 ± 11%), and 11, age-matched healthy volunteers were studied. From ECG and arterial pressure recordings up-BRS and down-BRS values were determined using the method of spontaneous sequences. The low frequency cross-spectral gain, the LF alpha was also determined. Percutaneous puncture of the peroneal nerves allowed determination of MSNA burst incidence (burst/100 cycles), which was correlated to corresponding diastolic pressure bins of 3 mmHg, yielding a sympathetic BRS, the BRSSY-incidence. RESULTS Up- and down-BRS could be calculated in 19% of the patients, LF alpha was determined in 69%. Those with missing cardiovagal BRS values showed diminished RR interval variation, and higher levels of NT-proBNP. The measurable cardiovagal BRS indices did not separate patients and healthy volunteers. BRSSY-incidence could be determined in 58% of the patients. The sympathetic gain as well as the burst incidence differed significantly between patients and healthy volunteers. Missing BRSSY-incidence was associated with higher burst incidence. CONCLUSION Cardiovagal BRS indices have limited value in differentiating healthy and heart failure subjects. Incalculable values among patients indicate more severe disease state. BRSSY-incidence does separate healthy and diseased population, the missing BRSSY-incidence values are related to increased sympathetic activity. Orv Hetil. 2021; 162(3): 91-98.