Real-time feedback on chest compression efficacy by hands-free carotid Doppler in a porcine model

Aim

Current guidelines for cardiopulmonary resuscitation (CPR) recommend a one-size-fits-all approach in relation to the positioning of chest compressions. We recently developed RescueDoppler, a hands-free Doppler ultrasound device for continuous monitoring of carotid blood flow velocity during CPR. The aim of the present study is to investigate whether RescueDoppler via real-time hemodynamic feedback, could identify both optimal and suboptimal compression positions.

Methods

In this model of animal cardiac arrest, we induced ventricular fibrillation in five domestic pigs. Manual chest compressions were performed for ten seconds at three different positions on the sternum in random order and repeated six times. We analysed Time Average Velocity (TAV) with chest compression position as a fixed effect and animal, position, and sequential time within animals as random effects. Furthermore, we compared TAV to invasive blood pressure from the contralateral carotid artery.

Results

We were able to detect changes in TAV when altering positions. The positions with the highest (range 19 to 48 cm/s) and lowest (6-25 cm/s) TAV were identified in all animals, with corresponding peak pressure 50-81 mmHg, and 46-64 mmHg, respectively. Blood flow velocity was, on average, highest at the middle position (TAV 33 cm/s), but with significant variability between animals (SD 2.8) and positions within the same animal (SD 9.3).

Conclusion

RescueDoppler detected TAV changes during CPR with alternating chest compression positions, identifying the position yielding maximal TAV. Future clinical studies should investigate if RescueDoppler can be used as a real-time hemodynamical feedback device to guide compression position.

Changes in cardiopulmonary exercise capacity and limitations 3-12 months after COVID-19

RATIONALE

To describe cardiopulmonary function during exercise 12 months after hospital discharge for coronavirus disease 2019 (COVID-19), assess the change from 3 to 12 months, and compare the results with matched controls without COVID-19.

METHODS

In this prospective, longitudinal, multicentre cohort study, hospitalised COVID-19 patients were examined using a cardiopulmonary exercise test (CPET) 3 and 12 months after discharge. At 3 months, 180 performed a successful CPET, and 177 did so at 12 months (mean age 59.3 years, 85 females). The COVID-19 patients were compared with controls without COVID-19 matched for age, sex, body mass index and comorbidity. Main outcome was peak oxygen uptake (V'_{O2  peak}).

RESULTS

Exercise intolerance (V'_{O2  peak} <80% predicted) was observed in 23% of patients at 12 months, related to circulatory (28%), ventilatory (17%) and other limitations including deconditioning and dysfunctional breathing (55%). Estimated mean difference between 3 and 12 months showed significant increases in V'_{O2  peak} % pred (5.0 percentage points (pp), 95% CI 3.1-6.9 pp; p<0.001), V'_{O2  peak}·kg^-1 % pred (3.4 pp, 95% CI 1.6-5.1 pp; p<0.001) and oxygen pulse % pred (4.6 pp, 95% CI 2.5-6.8 pp; p<0.001). V'_{O2  peak} was 2440 mL·min^-1 in COVID-19 patients compared to 2972 mL·min^-1 in matched controls.

CONCLUSIONS

1 year after hospital discharge for COVID-19, the majority (77%), had normal exercise capacity. Only every fourth had exercise intolerance and in these circulatory limiting factors were more common than ventilator factors. Deconditioning was common. V'_{O2  peak} and oxygen pulse improved significantly from 3 months.

Cardiac arrhythmias 3 months after hospitalization for COVID-19

Background

The long-term frequencies of cardiac arrhythmias in hospitalized coronavirus disease 2019 (COVID-19) patients have not been thoroughly investigated.

Purpose

To describe the prevalence of cardiac arrhythmias, 3–4 months after hospitalization for COVID-19.

Methods and results

Participants with COVID-19 discharged from five large Norwegian hospitals were invited to participate in a prospective cohort study. We examined 201 participants (44% females, mean age 58.5 years) with 24-hour electrocardiogram 3–4 months after discharge. Body mass index (BMI) was 28.3±4.5 kg/m2 (mean ± SD), and obesity (BMI &gt;30) was found in 70 participants (34%). Clinically significant arrhythmias were defined as; ventricular tachycardia (non-sustained or sustained), premature ventricular contractions (PVC) exceeding 200/24 h, or coupled PVC, atrial fibrillation/flutter, second-degree atrioventricular block (AV-block) type 2, complete AV-block, sinoatrial (SA) block exceeding 3 s, premature AV-nodal beats in bigeminy, supraventricular tachycardia (SVT) exceeding 30 s, and sinus bradycardia with less than 30 beats/min. High-sensitive cardiac troponin T (hs-cTnT) was measured at the 3-month follow-up.

Results

Cardiac arrhythmias were found in 27% (n=54) of the participants. Ventricular premature contractions and non-sustained ventricular tachycardia were the most common arrhythmias, found in 22% (n=44) of the participants. Premature ventricular contractions were the most frequent cardiac arrhythmia. More than 200 PVCs per day were observed in 37 participants (18%) with a mean of 1300 PVC/day, and in 35 (95%) of these participants, the PVCs were polymorphic.

Among 10 patients experiencing NSVT, 5 participants had previous CVD, including coronary heart disease (n=1), 1 atrial fibrillation, 2 venous thromboembolism, 4 heart failure. Atrial fibrillation was found in seven patients (3%), none of them of new-onset.

SA block &gt;3 seconds was only observed in one patient, and no incidence of high degree AV block was discovered. Pre-existing cardiovascular disease or hypertension (CVDH) were reported in 40% (n=81) of the participants. The CVDH group had an increased amount of arrhythmia compared to the group free of CVDH (p=0.04). High PVCs showed a fair correlation with hs-cTnT levels at 3 months (ρ=0.21 p=0.048).

Conclusions

Three months following hospital discharge with COVID-19, cardiac arrhythmia was found in every fourth participant and was associated with a higher concentration of hs-cTnT at 3 months. The clinical implications of persistent ventricular arrhythmia following COVID-19 is not clear, but ventricular ectopy has been linked to increased risk of cardiac disease, including cardiomyopathy and sudden cardiac death.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The National Association for Heart, Lung diseases and the Norwegian Health Association and Akershus University Hospital.

Cardiopulmonary exercise capacity and limitations 3 months after COVID-19 hospitalisation

Background

This study aimed to describe cardiopulmonary function during exercise 3 months after hospital discharge for COVID-19 and compare groups according to dyspnoea and intensive care unit (ICU) stay.

Methods

Participants with COVID-19 discharged from five large Norwegian hospitals were consecutively invited to a multicentre, prospective cohort study. In total, 156 participants (mean age 56.2 years, 60 females) were examined with a cardiopulmonary exercise test (CPET) 3 months after discharge and compared with a reference population. Dyspnoea was assessed using the modified Medical Research Council (mMRC) dyspnoea scale.

Results

Peak oxygen uptake (V′_O2 peak) <80% predicted was observed in 31% (n=49). Ventilatory efficiency was reduced in 15% (n=24), while breathing reserve <15% was observed in 16% (n=25). Oxygen pulse <80% predicted was found in 18% (n=28). Dyspnoea (mMRC ≥1) was reported by 47% (n=59). These participants had similar V′_O2 peak (p=0.10) but lower mean±sdV′_O2 peak·kg⁻¹ % predicted compared with participants without dyspnoea (mMRC 0) (76±16% versus 89±18%; p=0.009) due to higher body mass index (p=0.03). For ICU- versus non-ICU-treated participants, mean±sdV′_O2 peak % predicted was 82±15% and 90±17% (p=0.004), respectively. Ventilation, breathing reserve and ventilatory efficiency were similar between the ICU and non-ICU groups.

Conclusions

One-third of participants experienced V′_O2 peak <80% predicted 3 months after hospital discharge for COVID-19. Dyspnoeic participants were characterised by lower exercise capacity due to obesity and lower ventilatory efficiency. Ventilation and ventilatory efficiency were similar between ICU- and non-ICU-treated participants.

Oxygen uptake was reduced in one-third of participants 3 months after hospitalisation for COVID-19. The most common exercise limitation was deconditioning. Circulatory limitations to exercise were more common than ventilatory limitations.https://bit.ly/3jmVDQ6

High day-to-day and diurnal variability of oxidative stress and inflammation biomarkers in people with type 2 diabetes mellitus and healthy individuals

Objective: Assess the variability and differences in oxidative stress, antioxidant, and inflammatory biomarkers in people with type 2 diabetes mellitus (T2D) and healthy controls.

Methods: Ten men and women diagnosed with T2D and ten healthy matched controls (CON) were recruited. Participants had venous blood taken at six different time points on different days, three in the morning (after overnight fast) and three in the afternoon. Inflammation (IL-6, 8, 10 and TNF-α), oxidative stress/antioxidant biomarkers (F₂-isoprostanes, protein carbonyls, total antioxidant capacity (TAC), glutathione peroxidase activity, IL-6, 8 & 10 and TNF-α) were assessed.

Results: Biomarker concentrations were similar between groups. There was large variability in nearly all biomarkers for both groups. For inflammatory measures, intra-individual coefficients of variation (CV) ranged from 64.0–92.1% and 100.9–259.0% for inter-individual differences. CVs for oxidative stress markers were lower (7.4–31.2% for intra-individual and 8.6–43.0% for inter-individual). TAC had the lowest intra-individual CV – 7% for T2D and 8% for CON. Protein carbonyls were more variable in the afternoon (34% CV) compared to morning (24% CV) in CON. IL-6 intra-individual CV was different between groups for afternoon measurements (93% T2D, 60% CON).

Conclusion: Oxidative stress and inflammatory biomarkers show considerable variation in both T2D and healthy populations.

Trial registration:ClinicalTrials.gov identifier: NCT01206725.

Cardiac function in newborns of obese women and the effect of exercise during pregnancy. A randomized controlled trial

Background

The prevalence of maternal obesity is rising. Pre-pregnancy obesity is associated with later cardiovascular disease in the child and the underlying pathogenesis begins in early life. Therefore, pregnancy and infancy are key periods for potential intervention. The aim of this study was to study the cardiac function in newborns of obese women compared to newborns of normal-weight women, and to determine if exercise intervention during pregnancy could have an effect on cardiac function of newborns to obese women.

Material and methods

Fifty-five pregnant women, 51 obese (BMI ≥ 30 kg/m²) and four overweight (BMI 28–30 kg/m²), were randomized to an exercise training group (n = 27) or a control group (standard maternity care, n = 28). From gestational week 14 until delivery participants in the intervention group were offered supervised training sessions three times weekly. In addition, they were told to exercise at home once weekly. All newborns had an echocardiogram performed 1–3 days and 6–8 weeks after delivery. The results were compared with newborns of normal weight women (n = 20, standard maternity care).

Results

Newborns of obese women had an impaired systolic and diastolic cardiac function with reduced global strain, strain rate, tissue Doppler velocities and a thicker intraventricular septum at birth and after 6–8 weeks after delivery compared to newborns of normal weight women. Exercise had no statistically significant effect on either of the cardiac function parameters. The mean (± standard deviation) adherence to the exercise protocol was 1.3 ± 0.8 sessions per week for supervised training and 0.8 ± 0.7 sessions per week for home-based exercise training.

Conclusions

Newborns of obese women had reduced cardiac function and thicker intraventricular septum compared to newborns of normal weight women. Exercise training during pregnancy had no significant effect, potentially due to a low number of subjects and low adherence to the exercise protocol.

Trial registration

ClinicalTrials.gov NCT01243554.

Maternal obesity affects fetal myocardial function as early as in the first trimester

OBJECTIVE

To investigate cardiac function from 14 weeks' gestation in fetuses of obese pregnant women (FOW). Animal studies have shown that maternal obesity induces fibrosis in fetal myocardium. We hypothesized that fetal cardiac function would be impaired among FOW.

METHODS

A case-control study with longitudinal follow-up was performed at Trondheim University Hospital, Norway. In total, 80 pregnant women were included and the final population comprised 52 obese and 24 of normal weight (mean body mass index before pregnancy, 34.8 ± 4.1 vs 21.0 ± 2.2 kg/m(2) ; P < 0.001). The main outcome measures were global strain rate (GSR) and strain by tissue Doppler imaging, tissue Doppler velocities (TDVs) and interventricular septal thickness assessed by fetal echocardiography at gestational ages of 14, 20 and 32 weeks.

RESULTS

In FOW, fetal left ventricle (LV) and right ventricle (RV) GSR and strain were significantly lower than in fetuses of normal-weight pregnant women: LV GSR was 33.3% lower at 14 weeks, 22.4% lower at 20 weeks and 22.8% lower at 32 weeks of gestation (P < 0.001) with no difference in fetal heart rate. Systolic and late diastolic TDVs for LV were significantly lower from 20 weeks' gestation and remained lower throughout pregnancy. Fetal interventricular septum was 26.6% (P < 0.001) thicker in late pregnancy in FOW compared with normal-weight pregnancies.

CONCLUSIONS

At 14 weeks of gestation, we detected fetal myocardial dysfunction with reduced LV and RV GSR and strain in FOW compared with fetuses of women with normal weight. Our finding is alarming considering the high prevalence of obesity and may partly explain the predisposition of offspring to cardiovascular disease later in life.

Exercise Training Normalizes Timing of Left Ventricular Untwist Rate, but Not Peak Untwist Rate, in Individuals with Type 2 Diabetes and Diastolic Dysfunction: A Pilot Study

BACKGROUND

There is limited information regarding the role of left ventricular (LV) twist and the effect of exercise in type 2 diabetes (T2D). The aim of this study was to compare LV twist parameters in patients with T2D versus healthy control subjects and the effects of high-intensity interval exercise (HIIE) and moderate-intensity exercise (MIE) on LV twist in patients with T2D with diastolic dysfunction.

METHODS

This study, which included both prospective and retrospective components, included 47 patients with T2D and diastolic dysfunction and 37 healthy individuals. Patients with T2D were randomized to HIIE (4 × 4 min at 90%-95% of maximal heart rate, three times a week, 120 min/wk; n = 24) or MIE (210 min/wk; n = 23) for 12 weeks and examined with echocardiography (LV twist by speckle-tracking method) at baseline and posttest. The control subjects received no intervention and were matched according to age, gender, and body mass index to those completing the intervention.

RESULTS

In total, 37 subjects completed 12 weeks of MIE (n = 17) or HIIE (n = 20). LV peak untwist rate (UTR) was similar in patients with T2D and control subjects (P ˃ .05). At baseline, LV peak UTR, relative to total diastolic period, occurred 5.8 percentage points later in patients with T2D compared with control subjects (P = .004). Time to peak UTR was shortened by 6.5 percentage points (P = .002) and 7.7 percentage points (P < .001) after MIE and HIIE, respectively. Time to peak UTR was similar to that in control subjects after exercise interventions.

CONCLUSIONS

In patients with T2D and diastolic dysfunction, LV peak UTR was similar, but time to peak LV UTR was delayed compared with control subjects. Twelve weeks of endurance exercise normalized the timing of UTR.

Fast food increases postprandial cardiac workload in type 2 diabetes independent of pre-exercise: A pilot study

BACKGROUND

Type 2 diabetes aggravates the postprandial metabolic effects of food, which increase cardiovascular risk. We investigated the acute effects of fast food on postprandial left ventricular (LV) function and the potential effects of pre-exercise in type 2 diabetes individuals.

METHODS

We used a cross-over study including 10 type 2 diabetes individuals (7 male and 3 females; 53.4 ± 8.1 years; 28.3 ± 3.8 kg/m(2); type 2 diabetes duration 3.1 ± 1.8 years) and 10 controls (7 male and 3 females; 52.8 ± 10.1 years; 28.5 ± 4.2 kg/m(2)) performing high intensity interval exercise (HIIE; 40 min, 4 × 4 min intervals, 90-95% HRmax), moderate intensity exercise (MIE; 47 min, 70% HRmax) and no exercise (NE) in a random order 16-18 hours prior to fast-food ingestion. Baseline echocardiography, blood pressure and biochemical measurements were recorded prior to and 16-18 hours after exercise, and 30 minutes, 2 hours and 4 hours after fast food ingestion.

RESULTS

LV diastolic (peak early diastolic tissue velocity, peak early diastolic filling velocity), and systolic workload (global strain rate, peak systolic tissue velocity, rate pressure product) increased after consumption of fast food in both groups. In contrast to controls, the type 2 diabetes group had prolonged elevations in resting heart rate and indications of prolonged elevations in diastolic workload (peak early diastolic tissue velocity) as well as reduced systolic blood pressure after fast food consumption. No significant modifications due to exercise in the postprandial phase were seen in any group.

CONCLUSIONS

Our findings indicate that fast-food induces greater and sustained overall cardiac workload in type 2 diabetes individuals versus body mass index and age matched controls; exercise 16-18 hours pre-meal has no acute effects to the postprandial phase.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01991769.

Effect of 24 sessions of high-intensity aerobic interval training carried out at either high or moderate frequency, a randomized trial

Purpose

The training response of an intensified period of high-intensity exercise is not clear. Therefore, we compared the cardiovascular adaptations of completing 24 high-intensity aerobic interval training sessions carried out for either three or eight weeks, respectively.

Methods

Twenty-one healthy subjects (23.0±2.1 years, 10 females) completed 24 high-intensity training sessions throughout a time-period of either eight weeks (moderate frequency, MF) or three weeks (high frequency, HF) followed by a detraining period of nine weeks without any training. In both groups, maximal oxygen uptake (VO_2max) was evaluated before training, at the 9^th and 17^th session and four days after the final 24^th training session. In the detraining phase VO_2max was evaluated after 12 days and thereafter every second week for eight weeks. Left ventricular echocardiography, carbon monoxide lung diffusion transfer factor, brachial artery flow mediated dilatation and vastus lateralis citrate maximal synthase activity was tested before and after training.

Results

The cardiovascular adaptation after HF training was delayed compared to training with MF. Four days after ending training the HF group showed no improvement (+3.0%, p = 0.126), whereas the MF group reached their highest VO_2max with a 10.7% improvement (p<0.001: group difference p = 0.035). The HF group reached their highest VO_2max (6.1% increase, p = 0.026) twelve days into the detraining period, compared to a concomitant reduction to 7.9% of VO_2max (p<0.001) above baseline in the MF group (group difference p = 0.609).

Conclusion

Both HF and MF training of high-intensity aerobic exercise improves VO_2max. The cardiovascular adaptation following a HF programme of high-intensity exercise is however delayed compared to MF training.

Trial Registration

ClinicalTrials.gov NCT00733941.

Aerobic exercise training improves right- and left ventricular systolic function in patients with COPD

OBJECTIVE

The aim of this study was to investigate the effects of moderate continuous training (MCT) and high intensity aerobic interval training (AIT) on systolic ventricular function and aerobic capacity in COPD patients.

METHODS

Seventeen patients with COPD (64 ± 8 years, 12 men) with FEV1 of 52.8 ± 11% of predicted, were randomly assigned to isocaloric programs of MCT at 70% of max heart rate (HR) for 47 minutes) or AIT (~90% of max HR for 4×4 minutes) three times per week for 10 weeks. Baseline cardiac function was compared with 17 age- and sex-matched healthy individuals. Peak oxygen uptake (VO(2-peak)) and left (LV) and right ventricular (RV) function examined by echocardiography, were measured at baseline and after 10 weeks of training.

RESULTS

At baseline, the COPD patients had reduced systolic function compared to healthy controls (p < 0.05). After the training, AIT and MCT increased VO(2-peak) by 8% and 9% and work economy by 7% and 10%, respectively (all p < 0.05). LV and RV systolic function both improved (p < 0.05), with no difference between the groups after the two modes of exercise training. Stroke volume increased by 17% and 20%, LV systolic tissue Doppler velocity (S') by 18% and 17% and RV S' by 15% after AIT and MCT, respectively (p < 0.05).

CONCLUSION

Systolic cardiac function is reduced in COPD. Both AIT and MCT improved systolic cardiac function. In contrast to other patient groups studied, higher exercise intensity does not seem to have additional effects on cardiac function or aerobic capacity in COPD patients.

Severe poisoning with sotalol and verapamil. Recovery after 4 h of normothermic CPR followed by extra corporeal heart lung assist

In acute poisoning with beta-blocking drugs and calcium-channel blockers patients may present with serious symptoms. We present a case of life-threatening sotalol and verapamil intoxication in a 29-year-old female suffering from depression. She was admitted to our hospital a few hours after she had taken 3.6 g verapamil and 4.8 g sotalol. On being found the patient was breathing and had a palpable pulse. On admission the patient experienced a cardiovascular collapse and CPR was started. Echocardiography confirmed cardiac standstill. After 4 h of normothermic CPR, extra corporeal heart lung assist (ECHLA) was established. Vasoactive drugs could be stopped after 2 days with ECHLA, and after 5 days the patient was extubated. The patient experienced several complications (intestinal bleeding, transient nerve paralysis, and renal failure due to rhabdomyolysis) but made a complete recovery and started working 6 months after the poisoning. She was no longer depressed.