Post-discharge after surgery Virtual Care with Remote Automated Monitoring-1 (PVC-RAM-1) technology versus standard care: randomised controlled trial.

OBJECTIVE: To determine if virtual care with remote automated monitoring (RAM) technology versus standard care increases days alive at home among adults discharged after non-elective surgery during the covid-19 pandemic. DESIGN: Multicentre randomised controlled trial. SETTING: 8 acute care hospitals in Canada. PARTICIPANTS: 905 adults (≥40 years) who resided in areas with mobile phone coverage and were to be discharged from hospital after non-elective surgery were randomised either to virtual care and RAM (n=451) or to standard care (n=454). 903 participants (99.8%) completed the 31 day follow-up. INTERVENTION: Participants in the experimental group received a tablet computer and RAM technology that measured blood pressure, heart rate, respiratory rate, oxygen saturation, temperature, and body weight. For 30 days the participants took daily biophysical measurements and photographs of their wound and interacted with nurses virtually. Participants in the standard care group received post-hospital discharge management according to the centre's usual care. Patients, healthcare providers, and data collectors were aware of patients' group allocations. Outcome adjudicators were blinded to group allocation. MAIN OUTCOME MEASURES: The primary outcome was days alive at home during 31 days of follow-up. The 12 secondary outcomes included acute hospital care, detection and correction of drug errors, and pain at 7, 15, and 30 days after randomisation. RESULTS: All 905 participants (mean age 63.1 years) were analysed in the groups to which they were randomised. Days alive at home during 31 days of follow-up were 29.7 in the virtual care group and 29.5 in the standard care group: relative risk 1.01 (95% confidence interval 0.99 to 1.02); absolute difference 0.2% (95% confidence interval -0.5% to 0.9%). 99 participants (22.0%) in the virtual care group and 124 (27.3%) in the standard care group required acute hospital care: relative risk 0.80 (0.64 to 1.01); absolute difference 5.3% (-0.3% to 10.9%). More participants in the virtual care group than standard care group had a drug error detected (134 (29.7%) v 25 (5.5%); absolute difference 24.2%, 19.5% to 28.9%) and a drug error corrected (absolute difference 24.4%, 19.9% to 28.9%). Fewer participants in the virtual care group than standard care group reported pain at 7, 15, and 30 days after randomisation: absolute differences 13.9% (7.4% to 20.4%), 11.9% (5.1% to 18.7%), and 9.6% (2.9% to 16.3%), respectively. Beneficial effects proved substantially larger in centres with a higher rate of care escalation. CONCLUSION: Virtual care with RAM shows promise in improving outcomes important to patients and to optimal health system function. TRIAL REGISTRATION: ClinicalTrials.gov NCT04344665.

Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM): protocol for a randomized controlled trial.

BACKGROUND: After nonelective (i.e., semiurgent, urgent and emergent) surgeries, patients discharged from hospitals are at risk of readmissions, emergency department visits or death. During the coronavirus disease 2019 (COVID-19) pandemic, we are undertaking the Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM) trial to determine if virtual care with remote automated monitoring (RAM) compared with standard care will increase the number of days adult patients remain alive at home after being discharged following nonelective surgery. METHODS: We are conducting a randomized controlled trial in which 900 adults who are being discharged after nonelective surgery from 8 Canadian hospitals are randomly assigned to receive virtual care with RAM or standard care. Outcome adjudicators are masked to group allocations. Patients in the experimental group learn how to use the study's tablet computer and RAM technology, which will measure their vital signs. For 30 days, patients take daily biophysical measurements and complete a recovery survey. Patients interact with nurses via the cellular modem-enabled tablet, who escalate care to preassigned and available physicians if RAM measurements exceed predetermined thresholds, patients report symptoms, a medication error is identified or the nurses have concerns they cannot resolve. The primary outcome is number of days alive at home during the 30 days after randomization. INTERPRETATION: This trial will inform management of patients after discharge following surgery in the COVID-19 pandemic and offer insights for management of patients who undergo nonelective surgery in a nonpandemic setting. Knowledge dissemination will be supported through an online multimedia resource centre, policy briefs, presentations, peer-reviewed journal publications and media engagement. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT04344665.

Mid-term outcomes with adult endovascular treatment of coarctation of the aorta.

BACKGROUND: This study examines the contemporary medium- and long-term outcomes of endovascular repair of aortic coarctation in the adult. METHODS: We reviewed the clinical and imaging data of 56 consecutive adult patients with aortic coarctation who underwent endovascular repair at the Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada, from 2003 to 2018. RESULTS: There were 20 (35.7%) female and 36 (64.3%) male patients (including 9 re-intervention cases) with a mean age of 33.6 ± 13.6 years. Thirty-seven (66.1%) were treated with balloon-expandable covered stent and 12 (21.4%) were treated with balloon-expandable bare-metal stent. Pressure gradients decreased from baseline level of 27.99 ± 12.75 (8-70) mm Hg to 5.33 ± 4.42 (0-17.5) mm Hg following the procedure. There were 2 (3.6%) procedure related complications (aortic dissection [n = 1] and stent malposition [n = 1]). During a median (Q1 - Q3) follow up of 5.36 (2.28-7.58) years, 2 deaths (4.2%) and 9 (19%) re-interventions occurred, and the overall survival was 95.8%. CONCLUSION: Percutaneous coarctoplasty, with either covered or bare metal stents, is a safe and durable option for aortic coarctation repair with excellent long-term survival.

A Unique Intracardiac Shunt: Identifying Complex Anatomy in Reoperative Adult Congenital Heart Disease.

Adult patients with repaired congenital heart disease are presenting with previously unseen types of residual lesions and consequences of prior repair. Patients with d-transposition of the great arteries repaired with atrial switch operations are returning with dysrhythmias and atrioventricular valve disease requiring intervention. We present the challenging case of a young adult with a residual shunt identified on preoperative three-dimensional transthoracic echocardiography, the precise anatomy of which was only characterized intraoperatively.

Coronary artery compression three months after transcatheter pulmonary valve implantation.

We report a case of a 29-year-old man who developed exercised-induced myocardial infarction 3 months post Melody valve implantation. We introduce the concept of ruling out dynamic coronary artery compression by simulating transcatheter pulmonary valve implant while increasing cardiac output and thus aortic dimensions in the catheterization laboratory. © 2014 Wiley Periodicals, Inc.

Outcomes of consecutive patients referred for consideration for transcatheter aortic valve implantation from an encompassing health-care region.

Procedural outcomes for transcatheter aortic valve implantation (TAVI) are well described. However, limited information exists regarding patient screening and selection. Thus, the purpose of the study was to review consecutive patients referred for TAVI from an inclusive-defined population. The Mazankowski Alberta Heart Institute TAVI program has maintained a prospective database on all referred patients. Patients are reviewed in outpatient clinic attended by a nurse, cardiologist, cardiac surgeon, and administrative assistant. After workup is complete, a TAVI Heart Team conference occurs to accept or reject each patient. Since November 2009, 276 patients (145 men and 131 women) have been referred with a steady increase in the number of referrals annually. Mean age was 82.2 years (men 81.6 and women 82.8), with 13% aged <70 years. Mean EuroSCORE was 13.8 and mean STS score was 5.7. Of the referred patients, 34% received TAVI, 17% were rejected, 12% underwent open AVR, 10% refused TAVI, and 27% are currently being assessed or followed. There were no differences in the mean EuroSCORE (13.4 vs 14.3; p = 0.64) or STS scores (5.2 vs 6.4; p = 0.13) of those accepted for TAVI versus those who were not. In conclusion, a team-based approach to assess this complex patient population is essential to ensure efficient and comprehensive evaluation, in turn determining appropriate care allocation. With expansion of clinical experience and the evidence supporting TAVI, the Heart Teams defined to assess this patient population will be burdened with increased clinical commitment and require appropriate support.

Meta-analysis of aerobic interval training on exercise capacity and systolic function in patients with heart failure and reduced ejection fractions.

It is unknown if vigorous to maximal aerobic interval training (INT) is more effective than traditionally prescribed moderate-intensity continuous aerobic training (MCT) for improving peak oxygen uptake (Vo2) and the left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction. MEDLINE, PubMed, Scopus, and the Web of Science were searched using the following keywords: "heart failure," high-intensity interval exercise," "high-intensity interval training," "aerobic interval training," and "high-intensity aerobic interval training." Seven randomized trials were identified comparing the effects of INT and MCT on peak Vo2, 5 of which measured the LVEF at rest. The trials included clinically stable patients with heart failure with reduced ejection fraction with impaired left ventricular systolic function (mean LVEF 32%) who were relatively young (mean age 61 years) and predominantly men (82%). Weighted mean differences were calculated using a random-effects model. INT led to significantly higher increases in peak Vo2 compared with MCT (INT vs MCT, weighted mean difference 2.14 ml O2/kg/min, 95% confidence interval 0.66 to 3.63). Comparison of the effects of INT and MCT on the LVEF at rest was inconclusive (INT vs MCT, weighted mean difference 3.29%, 95% confidence interval -0.7% to 7.28%). In conclusion, in clinically stable patients with heart failure with reduced ejection fraction, INT is more effective than MCT for improving peak Vo2 but not the LVEF at rest.

Atrial septal defect closure in the elderly is associated with excellent quality of life, functional improvement, and ventricular remodelling.

BACKGROUND: While atrial septal defect (ASD) closure is known to improve morbidity and mortality in children and adults, data are only beginning to emerge about its role in elderly cohorts. The goals of this study were to compare outcomes after device or surgical closure of ASDs in the elderly, and to quantitatively assess quality of life. METHODS: Patients>60 years old who underwent ASD repair were studied. Functional status, arrhythmia burden, biventricular size and function were compared before and after ASD closure. Quality of life after ASD closure was assessed with the RAND SF-36 instrument. RESULTS: Sixty-seven patients, mean age of 68 years (range 60-86 years), were followed for 3.3 years. Nineteen percent underwent surgical closure and 81% underwent device closure. Major complication rates were 23% and 7% respectively with no procedure- related deaths. After surgical and device closure, quality of life was comparable to age-matched healthy controls, right ventricular end-diastolic dimension decreased by 10 mm (P<0.001), left ventricular end-diastolic dimension increased by 4 mm (P=0.001), biventricular function improved (right ventricular, P<0.001; left ventricular, P=0.007) and New York Heart Association class improved (P<0.001). Prevalence of atrial arrhythmias however, was unchanged. Beneficial effects were similar for patients treated surgically or with device closure. CONCLUSIONS: Given the favorable structural, functional, and quality of life outcomes after ASD closure in the elderly, advanced age alone should not be a contraindication to recommending surgical or device closure of an ASD.

Prolonged infusion of eptifibatide as bridge therapy between bare-metal stent insertion and cardiovascular surgery: case report and review of the literature.

Dual antiplatelet therapy with aspirin and clopidogrel is the standard of care after coronary artery stent insertion. Clopidogrel, however, has been associated with an increased risk of bleeding if it is used before coronary artery bypass grafting (CABG), and current guidelines recommend that it be discontinued at least 5 days before surgery. Compared with dual antiplatelet therapy, single antiplatelet therapy or the combination of an antiplatelet agent and an anticoagulant is associated with an increased risk of subacute stent thrombosis. Management of patients who require semiurgent CABG after stent insertion presents a clinical challenge. Intravenous glycoprotein IIb-IIIa inhibitors provide antiplatelet coverage with a shorter duration of action; thus, in theory, they may be useful for these clinical situations. We describe a 47-year-old man who came to the emergency department with sudden-onset, retrosternal chest pain. An electrocardiogram confirmed a diagnosis of ST-segment elevation myocardial infarction. The patient underwent angioplasty and received a bare-metal stent. Because significant disease was revealed in other arteries, CABG was scheduled. Clopidogrel was discontinued in preparation for surgery, and the patient received an infusion of eptifibatide 2 microg/kg/minute as bridging therapy to surgery for a total of 9 days. No major hemorrhagic or clinically evident thrombotic complications occurred before or after the surgery. Eptifibatide may be safe and effective as bridging therapy for patients with intracoronary stents who require CABG.

Forced euvolemic diuresis with mannitol and furosemide for prevention of contrast-induced nephropathy in patients with CKD undergoing coronary angiography: a randomized controlled trial.

BACKGROUND: Contrast-induced nephropathy is common in patients with coronary angiography. Mechanistically, forced euvolemic diuresis with mannitol and furosemide ought to prevent contrast-induced nephropathy. Our objectives are to: (1) undertake a randomized trial testing this hypothesis, and (2) conduct a meta-analysis of our findings with 2 earlier studies. STUDY DESIGN: (1) Randomized allocation-concealed controlled trial with blinded ascertainment of outcomes, and (2) random-effects meta-analysis of 3 trials. SETTING & PARTICIPANTS: Single-center study of consenting adults with serum creatinine level greater than 1.7 mg/dL undergoing coronary angiography; patients unable to tolerate fluid challenge or receiving dialysis were excluded. Two previous trials had randomly assigned 159 patients. INTERVENTION: Forced euvolemic diuresis with saline, mannitol, and furosemide compared with saline hydration controls. All patients were pretreated with at least 500 mL of half-normal saline before angiography; during and 8 hours after, urine output was replaced milliliter per milliliter with half-normal saline. OUTCOMES & MEASUREMENTS: The primary outcome was contrast-induced nephropathy within 48 hours of the procedure, defined as a 0.5-mg/dL absolute or 25% relative increase in creatinine level. RESULTS: Overall, 92 patients were allocated to intervention (n = 46) or control (n = 46). Mean age was 64 +/- 14 (SD) years, 23% were women, 37% had diabetes, 47% used oral furosemide, mean creatinine level was 2.8 +/- 1.6 mg/dL, and most patients (72%) underwent diagnostic catheterization. Patients had a net positive fluid balance (389 +/- 958 mL for intervention versus 655 +/- 982 mL for controls; P = 0.2). Contrast-induced nephropathy occurred in 23 (50%) intervention patients versus 13 (28%) controls (relative risk, 1.77; 95% confidence interval, 1.03 to 3.05; P = 0.03; adjusted odds ratio, 3.73; P = 0.03). Within 48 hours, creatinine level had increased by 0.8 +/- 1.1 mg/dL with intervention versus 0.2 +/- 0.6 mg/dL for controls (P = 0.002). Overall, 11 (12%) patients died or required dialysis, with no difference according to allocation status (P = 0.5). Random-effects meta-analysis of published data (3 trials; 251 patients) suggests furosemide-based interventions lead to significant harm compared with hydration: pooled relative risk, 2.15; 95% confidence interval, 1.37 to 3.37; I(2) = 0%. LIMITATIONS: Small single-center study that cannot determine whether harms were related to furosemide, mannitol, or a combination. CONCLUSIONS: Forced euvolemic diuresis led to a significantly increased risk of contrast-induced nephropathy. This strategy should be abandoned, and our results suggest that oral furosemide therapy perhaps should be held before angiography.

Impaired pulmonary oxygen uptake kinetics and reduced peak aerobic power during small muscle mass exercise in heart transplant recipients.

We examined peak and reserve cardiovascular function and skeletal muscle oxygenation during unilateral knee extension (ULKE) exercise in five heart transplant recipients (HTR, mean +/- SE; age: 53 +/- 3 years; years posttransplant: 6 +/- 4) and five age- and body mass-matched healthy controls (CON). Pulmonary oxygen uptake (Vo(2)(p)), heart rate (HR), stroke volume (SV), cardiac output (Q), and skeletal muscle deoxygenation (HHb) kinetics were assessed during moderate-intensity ULKE exercise. Peak exercise and reserve Vo(2)(p), Q, and systemic arterial-venous oxygen difference (a-vO(2diff)) were 23-52% lower (P < 0.05) in HTR. The reduced Q and a-vO(2diff) reserves were associated with lower HR and HHb reserves, respectively. The phase II Vo(2)(p) time delay was greater (HTR: 38 +/- 2 vs. CON: 25 +/- 1 s, P < 0.05), while time constants for phase II Vo(2)(p) (HTR: 54 +/- 8 vs. CON: 31 +/- 3 s), Q (HTR: 66 +/- 8 vs. CON: 28 +/- 4 s), and HHb (HTR: 27 +/- 5 vs. CON: 13 +/- 3 s) were significantly slower in HTR. The HR half-time was slower in HTR (113 +/- 21 s) vs. CON (21 +/- 2 s, P < 0.05); however, no significant difference was found between groups for SV kinetics (HTR: 39 +/- 8 s vs. CON 31 +/- 6 s). The lower peak Vo(2)(p) and prolonged Vo(2)(p) kinetics in HTR were secondary to impairments in both cardiovascular and skeletal muscle function that result in reduced oxygen delivery and utilization by the active muscles.

Effect of acute increases in pulmonary vascular pressures on exercise pulmonary gas exchange.

The purpose of this study was to determine the effect of acute increases in pulmonary vascular pressures, caused by the application of lower-body positive pressure (LBPP), on exercise alveolar-to-arterial PO2 difference (A-aDO2), anatomical intrapulmonary (IP) shunt recruitment, and ventilation. Eight healthy men performed graded upright cycling to 90% maximal oxygen uptake under normal conditions and with 52 Torr (1 psi) of LBPP. Pulmonary arterial (PAP) and pulmonary artery wedge pressures (PAWP) were measured with a Swan-Ganz catheter. Arterial blood samples were obtained from a radial artery catheter, cardiac output was calculated by the direct Fick method, and anatomical IP shunt was determined by administering agitated saline during continuous two-dimensional echocardiography. LBPP increased both PAP and PAWP while upright at rest, and at all points during exercise (mean increase in PAP and PAWP 3.7 and 4.0 mmHg, respectively, P<0.05). There were no differences in exercise oxygen uptake or cardiac output between control and LBPP. Despite the increased PAP and PAWP with LBPP, A-aDO2 was not affected. In the upright resting position, there was no evidence of shunt in the control condition, whereas LBPP caused shunt in one subject. At the lowest exercise workload (75 W), shunt occurred in three subjects during control and in four subjects with LBPP. LBPP did not affect IP shunt recruitment during subsequent higher workloads. Minute ventilation and arterial PcO2 were not consistently affected by LBPP. Therefore, small acute increases in pulmonary vascular pressures do not widen exercise A-aDO2 or consistently affect IP shunt recruitment or ventilation.

Does fitness level modulate the cardiovascular hemodynamic response to exercise?

Subjects with greater aerobic fitness demonstrate better diastolic compliance at rest, but whether fitness modulates exercise cardiac compliance and cardiac filling pressures remains to be determined. On the basis of maximal oxygen consumption (VO2max), healthy male subjects were categorized into either low (LO: VO2max=43+/-6 ml.kg-1.min-1; n=3) or high (HI: VO2max=60+/-3 ml.kg-1.min-1; n=5) aerobic power. Subjects performed incremental cycle exercise to 90% Vo(2max). Right atrial (RAP) and pulmonary artery wedge (PAWP) pressures were measured, and left ventricular (LV) transmural filling pressure (TMFP=PAWP-RAP) was calculated. Cardiac output (CO) and stroke volume (SV) were determined by direct Fick, and LV end-diastolic volume (EDV) was estimated from echocardiographic fractional area change and Fick SV. There were no between-group differences for any measure at rest. At a submaximal workload of 150 W, PAWP and TMFP were higher (P<0.05) in LO compared with HI (12 vs. 8 mmHg, and 9 vs. 4 mmHg, respectively). At peak exercise, CO, SV, and EDV were lower in LO (P<0.05). RAP was not different at peak exercise, but PAWP (23 vs. 15 mmHg) and TMFP (12 vs. 6 mmHg) were higher in LO (P<0.05). Compared with less fit subjects, subjects with greater aerobic fitness demonstrated lower LV filling pressures during exercise, whereas SV and EDV were either similar (submaximal exercise) or higher (peak exercise), suggesting superior diastolic function and compliance.

The significance of cardiac surgery scars in adult patients with congenital heart disease.

BACKGROUND: Scars resulting from heart surgery mark patients for life, yet their effect on patients' well-being is unknown. AIM: To determine what spheres of life may be affected by surgical chest scarring. METHODS: A preliminary questionnaire asked 10 random patients at our adult congenital heart disease clinic to describe personal consequences (if any) of having a cardiac surgery scar. Results provided the basis to design another questionnaire which asked specific questions and attempted to rate the effect of scars on identified areas of concern. RESULTS: One hundred consecutive patients attending the clinic (53 males) aged 18 to 50 (mean 27 years) participated. Sixty percent reported that the scar affected them less now than in adolescence. The body was perceived as disfigured by 58%. The scar was concealed by 48% of patients. Attention to the scar made 19% of patients feel negative, 58% neutral and 23% positive. Chest scarring was associated with decreased self-esteem in 20% and decreased self-confidence in 18% of patients. Patients reported less effect of chest scarring on their choice of career, success in life, friendships, sexual relationships and choice of recreation. Sixty-one percent reported a positive effect on appreciation of health. CONCLUSION: Scars resulting from heart surgery may have a considerable effect on patients' body image and several aspects of everyday life.

Prolonged strenuous exercise alters the cardiovascular response to dobutamine stimulation in male athletes.

Prolonged strenuous exercise has been associated with transient impairment in left ventricular (LV) systolic and diastolic function that has been termed 'cardiac fatigue'. It has been postulated that cardiac beta-adrenoreceptor desensitization may play a central role; however, data are limited. Accordingly, we assessed the cardiovascular response to progressive dobutamine stimulation after prolonged strenuous exercise (2 km swim, 90 km bike, 21 km run). Nine experienced male athletes were studied: PRE (2-3 days before), POST (after) and REC (1-2 days later). The cardiovascular response to progressive continuous dobutamine stimulation (0, 5, 20, and 40 microg kg(-1) min(-1)) was assessed, including heart rate (HR), systolic blood pressure (SBP), LV cavity areas (two-dimensional echocardiography) and contractility (end-systolic elastance, SBP/end-systolic cavity area (ESCA)). POST there was limited evidence of myocardial necrosis (measured by troponin I), while catecholamines were elevated. HR was higher POST (mean +/-s.d.; PRE, 58 +/- 9; POST, 79 +/- 9; REC, 57 +/- 7 beats min(-1); P < 0.05), while SBP was lower (PRE, 127 +/- 15; POST, 116 +/- 9; REC, 121 +/- 12 mmHg; P < 0.05). A blunted HR, SBP and LV contractility (SBP/ESCA; PRE 29 +/- 6 versus POST 20 +/- 6 mmHg cm(-2); P < 0.05) response to dobutamine was demonstrated POST, with values returning towards baseline in REC. Following prolonged strenuous exercise, the chronotropic and inotropic response to dobutamine stimulation is blunted. This study supports the hypothesis that beta-receptor downregulation and/or desensitization may play a major role in prolonged-strenuous-exercise-mediated cardiac fatigue.

Intra-pulmonary shunt and pulmonary gas exchange during exercise in humans.

In young, healthy people the alveolar-arterial P(O(2)) difference (A-aDO(2)) is small at rest, but frequently increases during exercise. Previously, investigators have focused on ventilation/perfusion mismatch and diffusion abnormalities to explain the impairment in gas exchange, as significant physiological intra-pulmonary shunt has not been found. The aim of this study was to use a non-gas exchange method to determine if anatomical intra-pulmonary (I-P) shunts develop during exercise, and, if so, whether there is a relationship between shunt and increased A-aDO(2). Healthy male participants performed graded upright cycling to 90% while pulmonary arterial (PAP) and pulmonary artery wedge pressures were measured. Blood samples were obtained from the radial artery, cardiac output was calculated by the direct Fick method and I-P shunt was determined by administering agitated saline during continuous 2-D echocardiography. A-aDO(2) progressively increased with exercise and was related to (r = 0.86) and PAP (r = 0.75). No evidence of I-P shunt was found at rest in the upright position; however, 7 of 8 subjects developed I-P shunts during exercise. In these subjects, point bi-serial correlations indicated that I-P shunts were related to the increased A-aDO(2) (r = 0.68), (r = 0.76) and PAP (r = 0.73). During exercise, intra-pulmonary shunt always occurred when A-aDO(2) exceeded 12 mmHg and was greater than 24 l min(-1). These results indicate that anatomical I-P shunts develop during exercise and we suggest that shunt recruitment may contribute to the widened A-aDO(2) during exercise.

Blood volume expansion and cardiorespiratory function: effects of training modality.

PURPOSE: To evaluate the effects of different modalities of aerobic (i.e., interval (INT) and continuous (CONT)) training on cardiorespiratory function and the importance of training-induced blood volume (BV) expansion on aerobic power and LV function. We hypothesized that if modality-mediated differences in cardiorespiratory function exist after INT and CONT, they would be related directly to differences in training-induced hypervolemia. METHODS: We examined the effects of 12 wk of CONT and INT on BV, volume-regulatory hormones (angiotensin II, aldosterone, atrial natriuretic peptide), and cardiorespiratory function in 20 untrained males (mean age 30 +/- 4 (SD)). Participants were stratified (mass and VO2max) and randomly assigned to control, CONT, or INT. RESULTS: There were no significant changes in cardiorespiratory function or BV in the control group. Twelve weeks of continuous and interval training, respectively, resulted in significant changes in VO2max (23 +/- 18 vs 21 +/- 10%), peak stroke volume (20 +/- 18 vs 11 +/- 18%), and BV (12 +/- 9 vs 10 +/- 6%). Changes in VO2max were directly related to changes in BV (r = 0.47). Angiotensin II significantly increased after 1 wk of CONT and INT and thereafter returned to baseline values. There was no significant difference between the CONT and INT groups with regard to changes in vascular volumes, volume-regulatory hormones, and/or cardiorespiratory function. CONCLUSIONS: These data indicate that: 1) 12 wk of CONT and INT result in similar improvements in VO2max, and LV function and 2) training-induced hypervolemia accounts for approximately 47% of the changes in VO2max after CONT and INT.