title: Assessment of systolic and diastolic function in asymptomatic subjects using ambulatory monitoring with acoustic cardiography.
abstract: BACKGROUND
  Adequately recording diastolic heart sounds and systolic time intervals over longer periods is difficult. Thus, information on the circadian variation of these parameters in an ambulatory population is lacking. Moreover, age-related changes in the prevalence of diastolic heart sounds and measurements of systolic time intervals in an asymptomatic population have not been studied in continuous recordings.
  
  
  OBJECTIVE
  Diastolic heart sounds and systolic time intervals will have age and circadian variations that reflect known changes in cardiac function due to aging and circadian rhythms.
  
  
  METHODS
  We studied 128 asymptomatic subjects wearing an ambulatory monitor with acoustic cardiography. The recording spanned a mean duration of 14 hours, including sleep. Data were analyzed for the presence of third (S3) and fourth (S4) heart sounds and for systolic time intervals.
  
  
  RESULTS
  In these asymptomatic subjects, S3 was significantly more prevalent in those age <40 years than in those age >40 years, and significantly more pronounced during sleep in the younger group. Also, S4 was significantly more prevalent in those age >40 years and significantly more pronounced during sleep in those age >40 years. In contrast, time intervals reflecting systolic function showed less circadian variation and less worsening with age.
  
  
  CONCLUSIONS
  The nocturnal increase of S4 in the elderly reflects diastolic impairment-likely a result of changes in diastolic filling patterns with increasing age. An S3 after the age of 40 is a relatively uncommon finding and therefore should be a specific sign of cardiac disease. Continuous monitoring of diastolic heart sounds and systolic time intervals is possible using acoustic cardiography.
authors.affiliation: Division of Cardiology, Luzerner Kantonsspital, Lucerne, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Dillier
authors.forename: Michel
authors.initials: M
authors.lastname: Zuber
authors.forename: Patricia
authors.initials: P
authors.lastname: Arand
authors.forename: Susanne
authors.initials: S
authors.lastname: Erne
authors.forename: Paul
authors.initials: P
authors.lastname: Erne
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D058070:Asymptomatic Diseases; D002940:Circadian Rhythm; D003971:Diastole; D015716:Electrocardiography, Ambulatory; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis* / Q000503:physiopathology; D006339:Heart Rate; D006347:Heart Sounds; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*; D010701:Phonocardiography; D011237:Predictive Value of Tests; D012890:Sleep; D013599:Systole; D014481:United States; D016276:Ventricular Function