title: Hemodynamic effects of isometric exercise in hypertrophic cardiomyopathy: comparison with normal subjects.
abstract: BACKGROUND
  We assessed the hemodynamic effects of isometric exercise by an ambulatory radionuclide monitoring device (VEST) that measured left ventricular function in patients who had hypertrophic cardiomyopathy (HCM), with and without significant left ventricular outflow-tract obstruction at rest, compared with control subjects.
  
  
  RESULTS
  We studied 10 patients with obstructive HCM, 25 patients with nonobstructive HCM, and 11 control subjects. During VEST monitoring, all patients gripped a dynamometer at 75% of maximal strength for up to 5 minutes. End-diastolic, end-systolic, and stroke volumes; cardiac output; and systemic vascular resistance were expressed as a percentage of baseline. The mean exercise duration was similar among the 3 groups. During handgrip, heart rate, systolic blood pressure, and cardiac output increased significantly and similarly in the 3 groups. There was a significant difference in the lung activity between obstructive and nonobstructive HCM patients and control subjects (P <.001), with a fall in control subjects and no change in HCM patients, irrespective of obstruction. Control subjects showed a decrease in end-systolic volume (P =.02) and an increase in ejection fraction (P =.003) and stroke volume (P =.009), whereas these parameters did not change in HCM patients, irrespective of obstruction. Systemic vascular resistance increased in obstructive (P =.02) and nonobstructive (P <.01) HCM patients but did not change in control subjects.
  
  
  CONCLUSIONS
  Isometric exercise causes an abnormal and similar adaptation to load changes in obstructive and nonobstructive HCM patients, as compared with control subjects.
authors.affiliation: Departments of Department of Clinical Medicine, Cardiovascular and Immunological Sciences and "Federico II" University School of Medicine, Naples, Italy.
authors.forename: Quirino
authors.initials: Q
authors.lastname: Ciampi
authors.forename: Sandro
authors.initials: S
authors.lastname: Betocchi
authors.forename: Anna
authors.initials: A
authors.lastname: Violante
authors.forename: Raffaella
authors.initials: R
authors.lastname: Lombardi
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Losi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Storto
authors.forename: Fiore
authors.initials: F
authors.lastname: Manganelli
authors.forename: Carlo Gabriele
authors.initials: CG
authors.lastname: Tocchetti
authors.forename: Mariano
authors.initials: M
authors.lastname: Aversa
authors.forename: Elpidio
authors.initials: E
authors.lastname: Pezzella
authors.forename: Filippo
authors.initials: F
authors.lastname: Finizio
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuocolo
authors.forename: Massimo
authors.initials: M
authors.lastname: Chiariello
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015637:Gated Blood-Pool Imaging / Q000379:methods; D018737:Hand Strength; D018056:Hemorheology / Q000379:methods; D006801:Humans; D007537:Isometric Contraction; D018670:Monitoring, Ambulatory / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D014694:Ventricular Outflow Obstruction / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology