title: Central and peripheral haemodynamic determinants of effort tolerance in patients with heart failure.
abstract: We studied central and peripheral hemodynamics and exercise tolerance in 24 patients with left ventricular dysfunction. All were in NYHA class II or III, and echocardiographic left ventricular ejection fraction was < 35% without pharmacologic influences. Patients underwent to treadmill test (Naughton protocol), cardiopulmonary upright bicycle test, and supine bicycle test with haemodynamic measurements. All tests were exhaustive. Average exercise time was 9 +/- 3.4 min, (range 3-20). Average ejection fraction (.28 +/- 0.65) dis not correlate with working capacity (r = .32), nor did left ventricular filling pressure (pulmonary capillary wedge pressure) at rest and at peak exercise (r = .29 and r = .02). Stroke volume and stroke volume index were on average depressed, with no variations during work; cardiac output and cardiac index were also depressed, with a significant increase at peak exercise (both p < .001). Systemic and pulmonary resistances were increased, but systemic resistances tended to decrease during effort (p < .001), while pulmonary resistances did not (p = NS). We subdivided patients according to systemic vascular resistances lower or higher than 1500 dynes.cm.sec-5 at rest; this identifies two different working capacities (low systemic vascular resistances 11.7 +/- 4.4 min, high systemic vascular resistances 6.9 +/- 3.2 min, p < .05). Patients were then divided in two groups: group I (rest stroke volume > 60 ml) and group II (rest stroke volume < 60 ml). Group I worked 11 +/- 5 min, group II 8.5 +/- 3 min (p < .05). We performed a linear regression analysis between cardiac output and systemic vascular resistances at rest and during exercise in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Divisione di Cardiologia, Fondazione Clinica del Lavoro, Pavia, Italia.
authors.forename: R
authors.initials: R
authors.lastname: Bonelli
authors.forename: M D
authors.initials: MD
authors.lastname: Etro
authors.forename: A
authors.initials: A
authors.lastname: Laporta
authors.forename: E
authors.initials: E
authors.lastname: Colombo
authors.forename: F
authors.initials: F
authors.lastname: Maslowsky
authors.forename: R
authors.initials: R
authors.lastname: Pedretti
authors.forename: C
authors.initials: C
authors.lastname: Anzà
authors.forename: F
authors.initials: F
authors.lastname: Santoro
authors.forename: A
authors.initials: A
authors.lastname: Gementi
authors.forename: E
authors.initials: E
authors.lastname: Gronda
mesh_terms: D000328:Adult; D000368:Aged; D005080:Exercise Test / Q000706:statistics & numerical data; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000453:epidemiology / Q000503:physiopathology; D010101:Oxygen Consumption; D012146:Rest / Q000502:physiology; D016277:Ventricular Function, Left