Blunted Chronotropic Response to Hypotension in Cough Syncope.
JACC Clin Electrophysiol
; 2(7): 818-824, 2016 12.
Article
em En
| MEDLINE
| ID: mdl-29759766
ABSTRACT
OBJECTIVES:
This study compared hemodynamic and chronotropic responses to cough in cough syncope (CS) patients to those in control subjects.BACKGROUND:
Cough syncope is an uncommon form of situational fainting variously attributed to both reflex and mechanical causes. We hypothesized that if baroreflex responses contribute to CS, post-cough hypotension should be associated with cardioinhibition comparable to that observed in other reflex faints.METHODS:
The study population consisted of 8 CS patients (group 1), 21 patients with vasovagal syncope (group 2), and 6 patients with nonvertiginous "lightheadedness" (group 3). Testing with patients seated included volitional coughing that achieved a transient blood pressure (BP) of ≥200 mm Hg. Beat-to-beat blood pressure (systolic blood pressure [SBP]) before cough, minimum cough-induced SBP and heart rate (HR) (beats/min) after cough, and HR change during cough-induced hypotension were recorded, along with SBP recovery time from SBP nadir after cough.RESULTS:
Compared to controls, cough-induced SBP drop was greater in CS patients (CS patients -48 ± 13.1 mm Hg vs. -29 ± 11.2 mm Hg for group 2 controls; p = 0.005; or -25 ± 10 mm Hg in group 3 controls; p = 0.02), and recovery time was longer (CS 46 ± 19 s vs. 11 ± 3.6 s in group 1 controls; p = 0.002; or 12 ± 5 s in group 3 controls; p = 0.01). Furthermore, despite greater induced hypotension, post-cough chronotropic response was less in CS patients (+15% above baseline rate) than in either group 2 (+31% above baseline rate; p < 0.001) or group 3 (+28%; p = 0.01) controls.CONCLUSIONS:
In CS patients, post-cough chronotropic response is blunted compared to that in controls despite greater cough-induced hypotension favoring baroreflex cardioinhibition contribution to the pathophysiology of cough syncope.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Síncope
/
Tosse
/
Frequência Cardíaca
/
Hipotensão
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
JACC Clin Electrophysiol
Ano de publicação:
2016
Tipo de documento:
Article