PubMed Health⌕ Search

Biomedical subjects

Massimo F Piepoli

Publications and source records attributed to Massimo F Piepoli.

33 records · Page 2Linked to original sources
PubMed2004

Differential contribution of dead space ventilation and low arterial pCO2 to exercise hyperpnea in patients with chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

In chronic heart failure (CHF), the abnormally large ventilatory response to exercise (VE/VCO(2) slope) has 2 conceptual elements: the requirement of restraining arterial partial pressure of carbon dioxide (pCO(2)) from increasing (because of an increased ratio between increased physiologic dead space and tidal volume [VD/VT]) and the depression of arterial pCO(2) by further increased ventilation, which necessarily implies an important non-carbon dioxide stimulus to ventilation. We aimed to assess the contribution of these 2 factors in determining the elevated VE/VCO(2) slope in CHF. Thirty patients with CHF underwent cardiopulmonary exercise testing (age 65 +/- 11 years, left ventricular ejection fraction 34 +/- 15%, peak oxygen uptake 15.2 +/- 4 ml/kg/min, VE/VCO(2) slope 36.4). At rest and during exercise, arterial pCO(2) was measured and VD was calculated and separated into serial and alveolar components. VD/VT decreased from 0.57 at rest to 0.44 at peak exercise (p <0.01). VE/VCO(2) slope was correlated with peak exercise VD/VT (r = 0.67), the serial VD/VT ratio (r = 0.64), and alveolar VD/VT ratio (r = 0.51) at peak exercise (all p <0.01). VE/VCO(2) slope was also correlated with arterial pCO(2) (r = -0.75, p <0.001). Despite this, arterial pCO(2) was not related to peak oxygen uptake (r = 0.2) or to arterial lactate (r = -0.25) and only weakly to New York Heart Association functional class (F = 3.7). First, the increased VE/VCO(2) slope was caused by both the high VD/VT ratio and by other mechanisms, as shown by low arterial pCO(2) during exercise. Second, this latter component (depression of arterial pCO(2)) was not related to conventional measures of heart failure severity.

Acidosis, Respiratory↗
PubMed2004

Prediction of mortality in chronic heart failure from peak oxygen consumption adjusted for either body weight or lean tissue.

BACKGROUND: Peak oxygen consumption (pVO2) reflects oxygen extraction from the skeletal muscles, but is routinely corrected for body weight. We hypothesized that correcting pVO2 for lean tissue rather than total body weight would improve the prediction of prognosis in patients with chronic heart failure (CHF). METHODS AND RESULTS: A total of 272 CHF outpatients (mean age 61 +/- 12 years, New York Heart Association [NYHA] class 2.3 +/- 0.8) underwent a cardiopulmonary exercise testing and body composition assessment by dual-energy X-ray absorptiometry. During a median follow-up of 608 days (range 8-3656), 75 patients died. Univariate survival analysis showed strong survival prediction from pVO2 adjusted for total weight or lean tissue (chi2 17.7, P < .001; chi2 27.5, P < .0001, respectively). Both predicted survival significantly in bivariate analysis, (chi2 4.6, P = .032; chi2 16.6, P < .0001). The predictive effects were independent of exercise protocol (treadmill versus cycle ergometer) (both P < .001). Multivariate analysis showed that pVO2 adjusted for lean tissue had prognostic importance independently of NYHA class, ejection fraction, and ventilation and carbon dioxide production slope (P < .05 for each). In patients with NYHA class I and II (n = 160), pVO2 adjusted for lean tissue predicted outcome (P = .03). CONCLUSION: Adjustment for lean tissue instead for body weight increases the prognostic power of pVO2, particularly in patients with mild heart failure.

Absorptiometry, Photon↗
PubMed2004

Putative contribution of prostaglandin and bradykinin to muscle reflex hyperactivity in patients on Ace-inhibitor therapy for chronic heart failure.

AIMS: In patients with chronic heart failure (CHF), an overactive muscle ergoreceptor reflex (chemo-afferents sensitive to the products of muscle work) is thought to play an important role in the origin of dyspnoea. We sought to investigate whether raised intra-muscular prostaglandins (PG) and bradykinin, as estimated by levels within the venous effluent from exercising skeletal muscle may be involved in symptom generation through the stimulation of the ergoreflex. METHODS AND RESULTS: In 19 stable CHF patients and 12 normal controls, cardiopulmonary exercise capacity (peak O2 consumption [peak VO2]) and the ergoreflex contribution to ventilation (post-handgrip regional circulatory occlusion method) were measured. Venous resting and exercise plasma PGE2, PGF1alpha and bradykinin concentrations were assessed. Eleven patients on angiotensin converting enzyme inhibitors and 10 controls were challenged with ketoprofen infusion (to inhibit PG synthesis and bradykinin activity). Patients vs. controls presented lower exercise tolerance (peak VO2 15.9+/-0.7 vs. 33.0+/-1.3 mL/kg/min), an increased ventilatory response to exercise (VE/VCO2 slope 43+/-2 vs. 27+/-0.9) (p<0.0001 for all comparisons). The overactive ergoreflex of CHF (5.1+/-1.3 vs. 0.1+/-0.3 L/min) was significantly related to the increase in PGF1alpha (adjusted R2=0.34, p<0.005) but not PGE2 (adjusted R2=0.16, p>0.05). The increased PG and bradykinin productions both at rest and during exercise in CHF were attenuated after ketoprofen infusion, associated with ergoreflex reduction (-5.1+/-2.2 L/min, p<0.05 vs. saline). CONCLUSION: In CHF, overactive muscle ergoreflex is associated with elevated blood concentration of PG and bradykinin. Modulation of these metabolite concentrations acutely reduces the muscle ergoreflex activity, which suggests a causative role in triggering and/or mediating the ergoreflex response.

Aged↗
PubMed2003

Skeletal muscle reflex in heart failure patients: role of hydrogen.

BACKGROUND: An important role of the increased stimulation of skeletal muscle ergoreceptors (intramuscular afferents sensitive to products of muscle work) in the genesis of symptoms of exertion intolerance in chronic heart failure (CHF) has been proposed. With the use of selective infusions and dietary manipulation methods, we sought to identify the role of H+, K+, lactate, and peripheral hemodynamics on ergoreflex overactivation. METHODS AND RESULTS: Ten stable CHF patients (aged 67.9+/-2.5 years, peak oxygen uptake 16.3+/-1.2 mL x kg(-1) x min(-1)) and 10 age-matched and sex-matched healthy subjects were studied. The ergoreflex contribution to ventilation was assessed by post-handgrip regional circulatory occlusion (PH-RCO) and computed as the difference in ventilation between PH-RCO and a control run without PH-RCO. This test was performed on 6 separate occasions. On each occasion a different chemical was infused (insulin, sodium nitroprusside, sodium bicarbonate, dopamine, or saline) or a 36-hour glucose-free diet was undertaken before the test. During all stages of the protocol, the local muscular blood effluent concentrations of H+, K+, glucose, and lactate were assessed. An ergoreflex effect on the ventilatory response was seen in patients (versus control subjects) during the saline infusions (6.7+/-2.3 L/min versus -0.1+/-0.5 L/min, P<0.01). The only intervention to significantly lower the ergoreflex was sodium bicarbonate (0.4+/-0.3 L/min versus -0.2+/-0.4 L/min in control subjects, P=NS; versus saline P<0.05), which also reduced H(+) concentration during exercise (47.4+/-1.3 versus 50.0+/-1.4 nmol/L on saline, P<0.05). CONCLUSION: A reduction of the H+ concentration by infusion of sodium bicarbonate abolishes the increased ergoreceptor activity in CHF, suggesting a role of H+ in ergoreflex activation, either directly or indirectly.

Aged↗
PubMed2003

Aerobic exercise physiology in a professional rugby union team.

INTRODUCTION: In professional rugby, different positional roles may require different levels of aerobic fitness. Forward and backline players from a team of elite rugby players were tested to evaluate the differences between the two groups. METHODS: 28 male players, 15 backs and 13 forwards, underwent maximal treadmill cardiopulmonary exercise testing (CPX), lung spirometry, a 3 km timed run, and body fat measurement. RESULTS: Peak oxygen uptake was higher in backs than in forwards (peak VO(2) 48.3+/-2.1 vs. 41.2+/-2.7 ml kg(-1) min(-1), P<0.05) with no significant difference in peak respiratory exchange ratio (1.08+/-0.02 vs. 1.07+/-0.02, P=NS), exercise time (1306+/-39.7 vs. 1217+/-25.1 s, P=NS) or time for 3 km run (667.5+/-14.1 vs. 699.0+/-20.7 s, P=NS). However, the forwards were taller and heavier (height 190.2+/-2.2 vs. 179.5+/-1.3 cm, P<0.001, body mass 104+/-2.4 vs. 86.3+/-1.7 kg, P<0.0001) and had a higher fat content (body fat percentage 12.8+/-0.8 vs. 9.7+/-0.6%, P<0.01) and forced expiratory volume in 1 s (FEV1, 4.9+/-0.1 vs. 4.5+/-0.2 l, P<0.05). There was a significant negative correlation between peak VO(2), 3 km run time (r=-0.45, P<0.05) and weight (r=-0.54, P<0.003) for all subjects. CONCLUSION: Backline players have a higher peak oxygen uptake per kilogram than forwards, although the cardiopulmonary exercise test duration, degree of anaerobic metabolism and 3 km run time are not significantly different. These results could be due to the two groups' different body structure, being shorter, lighter and having a lower percentage body fat. These differences, which are likely to be a result of selection for specific roles in the game, should be taken into account when evaluating aerobic fitness within a rugby team.

Adult↗
PubMed2003

Reproducibility of the measurement of the muscle ergoreflex activity in chronic heart failure.

BACKGROUND: A causative role for symptom generation in heart failure has been attributed to overactive muscle afferents, metaboreflex and mechanoreflex. We examined the reproducibility of the methods commonly used to assess these reflexes. MATERIAL AND METHODS: Twelve stable heart failure patients (62.8+/-2.4 years) and 18 normals were studied. The metaboreflex was evaluated on both leg and arm exercises, by performing two runs of 5-min submaximal handgrip and leg exercises. On one run the subjects recovered normally (control recovery), while on the other a post-exercise regional circulatory occlusion (PE-RCO) was induced in the exercising limb, to isolate the stimulation of the metaboreceptor after exercise. The metaboreflex was quantified as the difference in ventilation between the PE-RCO and the control recovery periods with respect to rest. The existence of a mechanoreflex was sought by comparing the ventilatory increment per unit of active work (dV(E)/dVO(2) ratio) between leg passive movement and active low level exercise. The coefficients of variation (CV) were computed to express the reproducibility of these reflexes in heart failure. RESULTS: The metaboreflex was overactive in patients vs. normals during both arm (7.2+/-2.8 l/min vs. 0.06+/-0.3 l/min) and leg (5.6+/-1.2 l/min vs. 0.5+/-0.2 l/min) tests. The mechanoreflex was not different between patients and normals: dV(E)/dVO(2) during passive movement 48.9+/-18.3 and 22.4+/-26.5; active exercise 42.3+/-18.4 and 31.9+/-18.7 (P=NS). In patients, the CV for the metaboreflex was 23.4% in the arm and 35.3% in the leg, while for the mechanoreflex test CV was 38.1% during passive movement and 21.1% during active exercise. CONCLUSION: The described method of measuring the muscle reflex activity shows an adequate reproducibility in heart failure patients.

Chemoreceptor Cells↗
PubMed2003

Muscle metaboreflex-induced increases in stroke volume.

PURPOSE: Accumulation of by-products of metabolism within skeletal muscle may stimulate sensory nerves, thus evoking a pressor response named muscle metaboreflex. The aim of this study was to evaluate changes in central hemodynamics occurring during the metaboreflex activation. METHODS: In seven healthy subjects, the metaboreflex was studied by postexercise regional circulatory occlusion at the start of the recovery from a mild rhythmic forearm exercise. Central hemodynamics was evaluated by means of impedance cardiography. RESULTS: The main findings of this study were that, with respect to rest, the metaboreflex: 1) raised mean blood pressure (+13%; P < 0.01); 2) enhanced myocardial contractility (-12% in preejection period/left ventricular ejection time ratio; P < 0.01); 3) prolonged diastolic time (+11%; P < 0.01); 4) increased stroke volume (+ 10%; P < 0.05); and 5) increased cardiac output (+6%; P < 0.05). These responses were present neither during recovery without circulatory occlusion nor during circulatory occlusion without prior exercise. Moreover, the metaboreflex did not affect systemic vascular resistance and induced bradycardia with respect to recovery without circulatory occlusion. CONCLUSION: These results suggest that the blood pressure response during metaboreflex activation after mild rhythmic exercise is strongly dependent on the capacity to increase cardiac output rather than due to increased vascular resistance.

Adult↗
PubMed2002

Tripling survival from sudden cardiac arrest via early defibrillation without traditional education in cardiopulmonary resuscitation.

BACKGROUND: Early defibrillation is the most important intervention affecting survival from sudden cardiac arrest (SCA). To improve public access to early defibrillation, we established Piacenza Progetto Vita (PPV), the first system of out-of-hospital early defibrillation by first-responder volunteers. METHODS AND RESULTS: The system serves a population of 173 114 residents in the Piacenza region of Italy. Equipment for the system comprises 39 semiautomatic external biphasic defibrillators (AEDs): 12 placed in high-risk locations, 12 in lay-staffed ambulances, and 15 in police cars; 1285 lay volunteers trained in use of the AED, without traditional education in cardiac pulmonary resuscitation, responded to all cases of suspected SCA, in coordination with the Emergency Medical System (EMS). During the first 22 months, 354 SCA occurred (72+/-12 years, 73% witnessed). The PPV volunteers treated 143 SCA cases (40.4%), with an EMS call-to-arrival time of 4.8+/-1.2 minutes (versus 6.2+/-2.3 minutes for EMS, P=0.05). Overall survival rate to hospital discharge was tripled from 3.3% (7 of 211) for EMS intervention to 10.5% (15 of 143) for PPV intervention (P=0.006). The survival rate for witnessed SCA was tripled by PPV: 15.5% versus 4.3% in the EMS-treated group (P=0.002). A "shockable" rhythm was present in 23.8% (34 of 143) of the PPV patients versus 15.6% (33 of 211) of the EMS patients (P=0.055). The survival rate from shockable dysrhythmias was higher for PPV versus EMS: 44.1% (15 of 34) versus 21.2% (7 of 33), P=0.046. The neurologically intact survival rate was higher in PPV-treated versus EMS-treated patients: 8.4% (12 of 143) versus 2.4% (5 of 211), P=0.009. CONCLUSIONS: Broad dissemination of AEDs for use by nonmedical volunteers enabled early defibrillation and tripled the survival rate for out-of-hospital SCA.

Cardiopulmonary Resuscitation↗
PubMed2002

Chemical mediators of the muscle ergoreflex in chronic heart failure: a putative role for prostaglandins in reflex ventilatory control.

BACKGROUND: The overactivity of ergoreceptors (intramuscular afferents sensitive to products of skeletal muscle work) may be responsible for the abnormal responses to exercise and symptoms of exercise intolerance in chronic heart failure (CHF); however, little is known of the chemical nature of the stimuli involved. We investigated biochemical factors (H+, VCO2, VO2, HCO3, K+, phosphate, lactate, PGE2, PGF(1alpha), and bradykinin) potentially involved in ergoreceptor activation. METHODS AND RESULTS: Sixteen stable patients with CHF (64.9+/-2.7 years, peak VO2 15.8+/-0.7 mL/kg per min) and 10 age-matched controls were studied. The ergoreceptor test involved two 5-minute handgrip exercises. On one occasion, the subjects recovered normally (control recovery), whereas on the other a posthandgrip regional circulatory occlusion was induced in the exercising arm, isolating the stimulation of the ergoreceptor after exercise. The ergoreflex was quantified as the difference in ventilation between the posthandgrip regional circulatory occlusion and the control recovery periods. During the protocol, the local muscular blood effluent concentrations of metabolic mediators were assessed. Patients had an ergoreflex effect on ventilation greater than controls (4.8+/-1.4 versus 0.4+/-0.1 L/min, P<0.01). During the ergoreflex test in patients, the following metabolites were elevated with respect to resting values in comparison with controls: PGE2 (3.7+/-0.7 versus 1.1+/-0.2 pg/mL), PGF(1alpha) (16.2+/-2.8 versus 7.2+/-1.2 pg/mL), and bradykinin (2.1+/-0.3 versus 1.0+/-0.1 pg/mL), P<0.05 for all comparisons. Only the increases in prostaglandins were predictors of the ergoreflex response (r>0.41, P<0.01). CONCLUSIONS: Although multiple metabolites are concentrated in exercising muscle in CHF, only prostaglandins correlated with ergoreflex activity, suggesting these factors as potential triggers to the exaggerated ergoreflex, which is characteristic of CHF. This may have important implications for novel therapies to improve exercise tolerance.

Aged↗
PubMed2002

Out-of-hospital early defibrillation successfully challenges sudden cardiac arrest: the Piacenza Progetto Vita project.

BACKGROUND: Early defibrillation is the most important intervention influencing survival following sudden cardiac arrest (SCA). In order to improve public access to early defibrillation, in North America several experiences of out-of-hospital early defibrillation by non-medical volunteers have been successfully implemented and demonstrated to improve survival. METHODS: Since 1999, in Piacenza, we have established "Progetto Vita", the first experience of out-of-hospital early defibrillation by non-medical volunteers in a medium-size European city. Thirty-nine semiautomatic external defibrillators were placed in Piacenza, Italy (266,531 inhabitants) and distributed in 12 high-risk locations, 12 lay-staffed ambulances and 15 police-cars. A total of 1285 lay volunteers were trained by the emergency medical system to intervene in all cases of suspected SCA. RESULTS: During the first 15 months, 203 codes for suspected SCA were dispatched; 197 were confirmed SCA. The overall survival was 5.6% (11/197): survival improved from 2.9% (4/134) with emergency medical system intervention to 11.1% (7/63) when the "Progetto Vita" was activated (p < 0.05). The survival rate on "shockable" rhythm was 43.7% in the group of patients treated by volunteers vs 16.6% in those treated by emergency medical system aid (p = 0.05). CONCLUSIONS: The widespread use of semiautomatic external defibrillators allows early defibrillation by non-medical volunteers and more than triples the survival rate following out-of-hospital SCA.

Electric Countershock↗
PubMed2002

Cardiostin 2002.

Explore the source record for details and available documents.

Chronic Disease↗