Valutazione della funzionalità cardiorespiratoria di soggetti cardiopatici: sviluppo di un test sottomassimale e suo impiego nella valutazione diagnostica e prognostica di 1016 soggetti cardiopatici

The stress tests are widely used in clinical practice to assess the circulatory and respiratory functions of both normal subjects and of subjects with chronic diseases, particularly cardiovascular. The maximum oxygen uptake (VO2max), which is obtained by the use of oxygen during maximal exercise, is widely recognized as the best functional assessment of cardiovascular capacity. During the 3 years of PhD I participated in the development of a sub-test that allows the indirect determination of maximum oxygen consumption. The test developed on 110 heart patients divided arbitrarily and not in Beta Blocked (n = 66) and Beta Blocked (n = 44) tested and running to a maximum cardiopulmonary exercise testing, runs on a treadmill and is the running Km a path of travel at constant speed and sub. The data (average speed and heart rate taken during the test) and the data of the subject under consideration (sex, age, weight, height) are placed into an algorithm: the value that is obtained, predicted VO2max was directly correlated with the VO2 max measured during a VO2max measured between TCP and VO2maxpredetto and not statistically different (P = ns) for both the NBB for the BB. The algorithms have been applied to a set of validation for both the BB and NBB that there were no significant differences between the values of VO2max and VO2maxPRED (P = ns) for the two groups. Finally was made a test of reliability has confirmed the validity of values. The test run performed from 1016 subjects with heart disease related to a cardiac rehabilitation service has been used to study the relationship between functional data, hospitalization and survival of these subjects which show that subjects in the highest quartile have lower risks of hospitalization and death from all causes compared to the other quartiles. The algorithms are highly suggestive and allow for indirect determination of VO2max for heart patients by allowing the clinical assessments of functional capabilities of individuals by reducing the risks of testing limits. We wanted to confirm the prognostic value of the data by checking whether there is a relationship between this and the need for inpatient hospitalization. The subdivision of the study population into quartiles on the basis of VO2maxPRED allowed to document how the group with the highest values of VO2maxPRED have a lower risk of hospitalization for all causes. The same result was confirmed dall'Hazard Ratio, which indicates that membership in the less efficient is a risk factor for hospitalization for any cause. Our results thus confirm that the value of VO2maxPRED from data provided by 1KTWT is a prognostic factor independent predictor of readmission for male subjects included in a cardiac rehabilitation program. Same thing goes for the risk of mortality, belong to groups with VO2maxPRED leads to a longer life expectancy. The increases in life expectancy of those who have suffered an acute cardiovascular event causes cardiac rehabilitation programs should bear a follow-up that can easily exceed ten years

Protocol for the Conconi Test and Determination of the Heart Rate Deflection Point

---A adequate warm up and increments in power output based on incremental cadence are necessary for the determination of the power output-heart rate relationship. Mathematical analysis of the data obtained allows the objective identification of the heart rate deflection point, a parameter useful both in sport and in clinical exercise testing

Respiratory muscle training improves thoracoabdominal coordination and work efficiency during incremental exercise in healthy subjects

none6Respiratory muscle training (RMT) by means of eucapnic hyperpnoea (Spirotiger®, Zurich, CH) is reported to increase exercise endurance but information on the effect of RMT on respiratory pattern and work efficiency during incremental exercise is lacking. Aim: to test the effect of RMT with Spirotiger on ventilatory pattern and aerobic function during incremental exercise in healthy subjects. Methods: 6 males collegiate athletes (age 20-24 years) involved in different disciplines such as soccer (2), rowing (1), triathlon (1), road skating (2) were recruited to partecipate in the study. A cardiopulmonary incremental test on a treadmill using a Balke protocol was performed by each subject before and after the RMT. VO2max, anaerobic threshold (AT) and the ΔVO2/ΔWR were determined. During the test ventilation and breathing pattern were evaluated by means of a portable inductive plethysmography (Lifeshirt, Vivometric, CA) and an index of thoracoabdominal coordination (the phase angle, Θ°) was calculated. RMT consisted of bouts of 20 min/day, 5 times/week, at Tidal Volume (Vt) = 60% of Vital Capacity (VC), respiratory frequency (ƒ) from 28 (first week) to 36. The remaining training schedule was unchanged. Results: after 4 weeks of RMT no changes were observed in VE, Vt, ƒ,VO2max, AT; Θ° at submaximal and maximal exercise significantly decreased from 24.2 (1.3) to 9.6 (0.5) p <0.001; ΔVO2/ΔW ml O2/W/min significantly decreased from 10.52 (.002) to 9.12 (.009), p =0.04. We conclude that 4 weeks RMT significantly improves thoracoabdominal coordination and work efficiency in healthy subjects during incremental exercise test.noneL. Pomidori; S. Uliari; G. Mazzoni; F. Manfredini; G. Grazzi; A. Cogo (Pomidori, Luca; Uliari, Simone; Mazzoni, Gianni; Manfredini, Fabio; Grazzi, Giovanni; Cogo, Annaluis

On the methodology of the Conconi Test

Recently Van Schuylenmbergh et al have compared the anaerobic threshold determined with five different methods, including the Conconi Test, with maximal lactate steady state in elite cyclists. With this letter we criticize the testing protocol employed by the authors in performing the Conconi test

Incremental exercise using progressive versus constant pedaling rates: A study in cardlac patients

PURPOSE: Cardiopulmonary exercise testing is widely used in clinical assessment and exercise prescription. However, significant differences in physiological responses can occur depending on testing protocol. The aim of this study was to evaluate the cardiopulmonary responses to different incremental cycle pedaling cadences in cardiac patients. ■ METHODS: Eleven men with coronary artery disease (CAD) and 12 men with chronic heart failure (CHF) performed 2 maximal cycle tests at constant cadence (60-70 rpm, at fixed cadence) and at progressive cadence. Peak values for oxygen uptake (VO2peak), workload (Wpeak), and heart rate (HRpeak); ventilatory threshold (VT); and the oxygen uptake (VO2) per unit work rate (WR) increment (VO2/WR) obtained using 2 protocols were determined. ■ RESULTS: Vo2peak and Wpeak, respectively, were higher during increasing cadence (INCR) compared with fixed cadence (FIX) protocol both in patients with CAD (32.7 5.4 vs 28.1 7.0 mL ˙ kg1 ˙ min1, P .01; 214 42 vs 150 28 W, P .001) and in patients with CHF (20.3 7.4 vs 17.2 5.5 mL ˙ kg1 ˙ min1, P .006; 133 45 vs 104 33 W, P .005). No differences were seen in HRpeak. Both in patients with CAD and in patients with CHF, O2 (21.7 5.5 vs 16.8 5.3 and 12.3 7.4 vs 9.3 2.8 mL ˙ kg1 ˙ min1) and HR (114 14 vs 98 13 and 92 17 vs 80 17 bpm) at VT were significantly higher in INCR than in FIX protocol. No differences were seen in workload at VT. Vo2/WR during INCR protocol were higher in patients with CAD (13.4 1.8 vs 9.5 2.6 mL ˙ kg1 ˙ W1, P .006) and patients with CHF (13.6 4.1 vs 8.7 1.9 mL ˙ kg1 ˙ W1, P .006). ■ DISCUSSION: These findings indicate that in tests at fixed cadence, there occurs an earlier activation of the anaerobic mechanisms leading to a premature exhaustion before a cardiopulmonary endpoint has been achieved.PURPOSE: Cardiopulmonary exercise testing is widely used in clinical assessment and exercise prescription. However, significant differences in physiological responses can occur depending on testing protocol. The aim of this study was to evaluate the cardiopulmonary responses to different incremental cycle pedaling cadences in cardiac patients.METHODS: Eleven men with coronary artery disease (CAD) and 12 men with chronic heart failure (CHF) performed 2 maximal cycle tests at constant cadence (60-70 rpm, at fixed cadence) and at progressive cadence. Peak values for oxygen uptake (VO(2peak)), workload (W(peak)), and heart rate (HR(peak)); ventilatory threshold (VT); and the oxygen uptake (VO(2)) per unit work rate (WR) increment (Delta VO(2)/Delta WR) obtained using 2 protocols were determined.RESULTS: Vo(2peak) and W(peak), respectively, were higher during increasing cadence (INCR) compared with fixed cadence (FIX) protocol both in patients with CAD (32.7 +/- 5.4 vs 28.1 +/- 7.0 mL . kg(-1) . min(-1), P = .01; 214 +/- 42 vs 150 +/- 28 W, P = .001) and in patients with CHF (20.3 +/- 7.4 vs 17.2 +/- 5.5 mL . kg(-1) . min(-1), P = .006; 133 +/- 45 vs 104 +/- 33 W, P = .005). No differences were seen in HR(peak). Both in patients with CAD and in patients with CHF, VO(2) (21.7 +/- 5.5 vs 16.8 +/- 5.3 and 12.3 +/- 7.4 vs 9.3 +/- 2.8 mL . kg(-1). min(-1)) and HR (114 +/- 14 vs 98 +/- 13 and 92 +/- 17 vs 80 +/- 17 bpm) at VT were significantly higher in INCR than in FIX protocol. No differences were seen in workload at VT.Delta Vo(2)/Delta WR during INCR protocol were higher in patients with CAD (13.4 +/- 1.8 vs 9.5 +/- 2.6 mL . kg(-1). W(-1), P = .006) and patients with CHF (13.6 +/- 4.1 vs 8.7 +/- 1.9 mL . kg(-1) . W(-1), P = .006).DISCUSSION: These findings indicate that in tests at fixed cadence, there occurs an earlier activation of the anaerobic mechanisms leading to a premature exhaustion before a cardiopulmonary endpoint has been achieved

Oxygen uptake attenuation at ventilatory threshold in men with coronary artery disease

Purpose: Maximal oxygen uptake (VO2) and ventilatory threshold (VT) are widely used to assess cardiorespiratory fitness in healthy people, as well as in patients with various clinical conditions. The aim of this study was to determine whether an attenuation of VO2 occurs above the VT in patients with stable coronary artery disease. Methods: A total of 33 male patients participating in an outpatient cardiac rehabilitation/secondary prevention program underwent maximal incremental cycle ergometry at increasing pedaling cadences up to the limit of tolerance. Ventilatory gas-exchange variables were measured breath by breath while work rate was recorded continuously. Ventilatory threshold was determined by a dual linear regression model (V-slope analysis). Result: Four patients were excluded from the analysis because they were unable to pedal at the increasing cadences required by the protocol. The remaining 29 patients successfully completed the test without complications or evidence of significant ST segment depression. The slope of the VO2/work rate relationship above the VT decreased significantly (- 44.6%on average) in 23 of the 26 patients in which VT was able to be determined. VO2 at the start of VO2 attenuation (VO2att) and at VT were highly correlated and in strong agreement (1637 ± 451 mL/min vs 1650 ± 473 mL/min, r 2=0.96, P <.01). Conclusions: VO2att does occur and coincides with the VT in the majority of patients tested with stable coronary artery disease

INFLUENCE OF A CUSTOM MADE MAXILLARY MOUTHGUARD ON EXERCISE PERFORMANCE OF AMATEUR ROAD CYCLISTS.

Aim: To evaluate the influence of a custom made maxillary mouthguard (Parabite Malpezzi®, PM) on submaximal and maximal physiological parameters determining performance in road cycling. Methods: Ten well-trained amateur road cyclists (35±5 yr.) performed an incremental cardiopulmonary test until exhaustion on a frictional braked cycle ergometer, with work rate (WR) increase of 15 watts per minute at a freely chosen pedaling cadence. WR, heart rate, oxygen consumption (VO2), carbon dioxide production, and ventilation at Lactate Threshold (LT), at Respiratory Compensation Point (RCP) and at maximal exercise (MAX) were determined in normal condition (C) and wearing PM, made with an original method based on gnathological and anthropometric parameters. Cycling economy was also evaluated by analyzing the slope of the VO2/WR (ΔVO2/ΔWR, mL/watt/min) relationship during the test in the two experimental conditions. Results: Wearing PM compared to C resulted in an average significant 6% and 4% increases of WR at RCP (281±32 vs 266±19 watts, P=0.04) and at MAX (353±44 vs 339±38 watts, P=0.004) respectively. Wearing PM also resulted in a 8% lower ΔVO2/ΔWR (9.5±1.1 vs 10.3±1.1 mL/watt/min, P=0.06) while did not significantly alter any of the other measured parameters at LT, RCP and MAX. Conclusion: Wearing individually fitted maxillary mouthguard enhanced cycling economy and exercise performance above Lactate Threshold, while did not affect other parameters generally associated with cycling performance. These preliminary results provide support to encourage athletes to correct jaw posture and occlusal clench in order to improve exercise performance

Identification of a VO2 deflection point coinciding with the HR deflection point and ventilatory threshold in elite cyclists

Purposes: 1) to compare the pattern of the work rate (WR)/VO2 and of the WR/heart rate (HR) relationship in incremental cycling; 2) to ascertain the occurrence of a VO2deflection (VO2def) and to compare it with the HR deflection point (HRdef ); 3) to compare the VO2 at the ventilatory threshold (VT) and at VO2def, if present. Methods: 24 professional cyclists performed an incremental test on a wind-load cycle ergometer. WR, HR,VO2 and VCO2 were recorded. Results: 1) The WR/VO2 relationship was linear up to submaximal WR and curvilinear thereafter, due to VO2attenuation. The WR and VO2 at the beginning of the attenuation (VO2def) were mathematically determined in all subjects. The ratio ΔWR/Δ VO2 up to VO2def was significantly lower than above VO2def (90 ± 11 versus 133 ± 35 watts/L.min-1, P < 0.0001). 2) The WR/HR relationship was linear up to submaximal WR and curvilinear thereafter. The WR and HR at the beginning of the HR attenuation (HRdef) were mathematically determined in all subjects. 3) The WR values at VO2def and at HRdef (329 ± 32 and 326 ± 34 watts) were significantly correlated (R2 = 0.96, P < 0.0001) and in good concordance (limits of agreement from -4.7 to 3.2%, Bland-Altman analysis). 4) The VO2 at VAT was determined in all subjects. The VO2values at VO2def and at VT were significantly correlated (R2 = 0.99, P < 0.0001) and in strong concordance (limits of agreement from -1.9 to 1.0%, Bland-Altman analysis). Conclusion: A VO2 attenuation starting at 82% VO2maxin coincidence with HRdef and VT has been demonstrated in professional cyclists during incremental tests.Grazzi, G, Mazzoni, G, Casoni, I, Uliari, S, Collini, G, van der Heide, L, and Conconi, F. Identification of a (V) over doto(2) deflection point coinciding with the heart rate deflection point and ventilatory threshold in cycling. J Strength Cond Res 22: 1116-1123, 2008-The purposes of this study were to compare the patterns of the work rate (WR)-(V) over doto(2) and WR-heart rate (HR) relationships in incremental cycling, to ascertain the occurrence of a (V) over doto(2) deflection ((V) over doto(2)def) coinciding with the HR deflection point (HRdef), and to determine whether the (V) over doto(2)def, if present, coincides with the ventilatory anaerobic threshold (VT). Twenty-four professional cyclists performed a maximal incremental test on a wind-load cycle ergometer. Work rate, HR, (V) over doto(2), and (V) over dotco(2) were recorded. The WR-(V) over doto(2) relationships obtained were linear up to submaximal WR and curvilinear thereafter and thus described a (V) over doto(2)def. The WR and (V) over doto(2) at (V) over doto(2)def were mathematically determined for all subjects. The ratio of Delta WR.Delta(V) over doto(2)(-1) up to (V) over doto(2)def was significantly lower than that above (V) over doto(2)def (90 +/- 11 W.L-1 .min(-1) versus 133 +/- 35 W .L-1 .min(-1), p < 0.0001). The WR-HR relationships obtained were linear up to submaximal WR and curvilinear thereafter. The WR and HR at HRdef were mathematically determined for all subjects. The WR values at (V) over doto(2)def and at HRdef (329 +/- 32 W and 326 +/- 34 W) were significantly correlated (R-2 = 0.96, p < 0.0001) and in good concordance (limits of agreement from -4.7% to 3.2%, Bland-Altman analysis). The (V) over doto(2) at VT was then determined for all subjects. The (V) over doto(2) values at (V) over doto(2)def and at VT were significantly correlated (R-2 = 0.99, p < 0.0001) and in strong concordance (limits of agreement from -1.9% to 1.0%, Bland-Altman analysis). In conclusion, a (V) over doto(2)def coinciding with HRdef and VT was shown. This confirms that the determination of the WR-HR relationship and of HRdef is a practical and noninvasive means of identifying anaerobic threshold