ECG Heart Rate Research Articles

Abstract 11046: Chronic Obstructive Pulmonary Disease and Sudden Cardiac Death in Hypertensive Patients: The LIFE Study

Background: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of cardiovascular (CV) disease and CV mortality. A recent large, population-based study suggested that COPD is associated with an increased risk of sudden cardiac death (SCD). However, whether COPD predicts SCD in hypertensive patients during aggressive blood pressure (BP) lowering has not been examined. Methods: Risk of SCD was examined in relation to a history of COPD in 9193 hypertensive patients with ECG left ventricular hypertrophy (LVH) who were randomly assigned to losartan- or atenolol-based treatment. A history of COPD was present in 385 patients (4.2%). SCD, a prespecified secondary endpoint in LIFE, was defined as death that was sudden and unexpected, including observed arrhythmic deaths and those not attributable to myocardial infarction (MI), intractable heart failure (HF) or other identifiable cause, occurring within 24 hours of symptom onset or when the subject was last seen alive if unwitnessed SCD. Results: During mean follow-up of 4.8±0.9 years, 178 patients (2.4%) had SCD, with a higher incidence rate per 1000 person-years in those with COPD: 9.0; 95% CI, 6.1-11.9 vs 3.8; 95% CI, 3.4-4.2; p=0.001. In a univariate Cox model, COPD was associated with a > 2-fold increased risk of SCD (HR 2.36, 95% CI 1.42-3.95, p=0.001). In a multivariable Cox regression model that adjusted for other predictors of SCD in this population (randomized treatment, age, gender, race, history of atrial fibrillation, stroke or transient ischemic attack, baseline serum creatinine and glucose entered as standard covariates and incident MI, incident HF and in-treatment diastolic pressure, heart rate, QRS duration, HDL cholesterol, and use of hydrochlorothiazide or a statin entered as time-varying covariates), COPD remained associated with a nearly 2-fold increased risk of SCD (HR, 1.82; 95% CI, 1.04-3.18, p=0.035). Conclusions: COPD is associated with an increased risk of SCD in hypertensive patients. The higher SCD risk in COPD patients persists after adjusting for the higher prevalence of risk factors in COPD patients, in-treatment blood pressure, incident MI and HF, and the established predictive value of in-treatment ECG LVH and heart rate for SCD in this population.

SenseMyHeart: A cloud service and API for wearable heart monitors.

In the era of ubiquitous computing, the growing adoption of wearable systems and body sensor networks is trailing the path for new research and software for cardiovascular intensity, energy expenditure and stress and fatigue detection through cardiovascular monitoring. Several systems have received clinical-certification and provide huge amounts of reliable heart-related data in a continuous basis. PhysioNet provides equally reliable open-source software tools for ECG processing and analysis that can be combined with these devices. However, this software remains difficult to use in a mobile environment and for researchers unfamiliar with Linux-based systems. In the present paper we present an approach that aims at tackling these limitations by developing a cloud service that provides an API for a PhysioNet-based pipeline for ECG processing and Heart Rate Variability measurement. We describe the proposed solution, along with its advantages and tradeoffs. We also present some client tools (windows and Android) and several projects where the developed cloud service has been used successfully as a standard for Heart Rate and Heart Rate Variability studies in different scenarios.

Evaluation of accuracy and reliability of PulseOn optical heart rate monitoring device.

PulseOn is a wrist-worn optical heart rate (HR) monitor based on photoplethysmography. It utilizes multi-wavelength technology and optimized sensor geometry to monitor blood flow at different depths of skin tissue, and it dynamically adapts to an optimal measurement depth in different conditions. Movement artefacts are reduced by adaptive movement-cancellation algorithms and optimized mechanics, which stabilize the sensor-to-skin contact. In this paper, we evaluated the accuracy and reliability of PulseOn technology against ECG-derived HR in laboratory conditions during a wide range of physical activities and also during outdoor sports. In addition, we compared the performance to another on-the-shelf wrist-worn consumer product Mio LINK(®). The results showed PulseOn reliability (% of time with error <;10bpm) of 94.5% with accuracy (100% - mean absolute percentage error) 96.6% as compared to ECG (vs 86.6% and 94.4% for Mio LINK(®), correspondingly) during laboratory protocol. Similar or better reliability and accuracy was seen during normal outdoor sports activities. The results show that PulseOn provides reliability and accuracy similar to traditional chest strap ECG HR monitors during cardiovascular exercise.

Evaluation of in‐hospital electrocardiography versus 24‐hour Holter for rate control in dogs with atrial fibrillation

To determine if the in-clinic ECG-derived heart rate could predict the at-home Holter-derived 24-hour average heart rate (Holter24h ), and whether it is useful to identify slow versus fast atrial fibrillation in dogs. 82 pairs of 1-minute ECGs and 24-hour Holter recordings were acquired in 34 dogs with atrial fibrillation. The initial 24-hour Holter was used to test if the ECG heart rate can identify dogs with "slow" versus "fast" atrial fibrillation based on a Holter24h threshold value of 140 bpm. ECG heart rate overestimated Holter24h by 26 bpm (95% CI: 3 bpm, 48 bpm; P < 0 · 015) with a 95% limit of agreement of -21 to 83 bpm. The in-clinic ECG-derived heart rate Ä155 bpm had a sensitivity of 73% and a specificity of 100% for identifying a Holter24h HR Ä140 bpm; an in-clinic ECG-derived HR <160 bpm had a sensitivity and specificity of 91% each. In-clinic ECG assessment of heart rate in dogs with atrial fibrillation does not reliably predict the heart rate in their home environment. However, an in-clinic heart rate greater than 155 bpm is useful in identifying "fast" atrial fibrillation, allowing clinicians to stratify which case may benefit from antiarrhythmic therapy.

Cardiac safety profile of etamicastat, a novel peripheral selective dopamine-β-hydroxylase inhibitor in non-human primates, human young and elderly healthy volunteers and hypertensive patients

The aim of this work was to evaluate the cardiac risk for etamicastat, a peripheral reversible dopamine-β-hydroxylase inhibitor. Etamicastat blocked the hERG current amplitude with an IC50 value of 44μg/ml. Etamicastat had no substantial effects on arterial blood pressure, heart rate and the PR interval in male Cynomolgus monkeys when administered orally up to 90mg/kg. Administered orally at 15 and 45mg/kg/day in female and male Cynomolgus monkey for 91days, etamicastat had no effect on heart rate and the waveform or intervals of the electrocardiogram. At the highest dose level of 45mg/kg, mean plasma concentrations of etamicastat ranged from 1875 to 3145ng/ml on Day 1 and Day 91 of treatment, respectively. The effect of age on the tolerability and pharmacokinetics of etamicastat in elderly (≥65years) and young adult (18–45 years) subjects showed that supine systolic (SBP) and diastolic (DBP) blood pressure, ECG heart rate, PR interval, QRS duration and QTcF interval were not affected following once-daily administration of 100mg/day etamicastat for 7days. In hypertensive patients the decrease of blood pressure tended to be more important in subjects who had received etamicastat (50, 100 and 200mg) than in subjects who had received placebo. No clinically significant out-of-range values in vital signs or ECG parameters, ECG heart rate, PR interval, QRS duration and QTcF interval were observed in hypertensive subjects following once-daily administration of etamicastat for 10days. In conclusion, etamicastat is not likely to prolong the QT interval at therapeutic doses.

Electrical Changes in Resting, Exercise, and Holter Electrocardiography in Fabry Cardiomyopathy.

In Fabry cardiomyopathy, little is known about the interaction between its key feature of myocardial replacement fibrosis and changes in resting, Holter, and exercise electrocardiography (-ECG). Resting ECG, 24-h Holter ECG, and exercise ECG were performed in 95 patients (50 women) with Fabry disease, staged using cardiac magnetic resonance imaging to measure left ventricular fibrosis. With resting ECG, T alterations were seen in patients with cardiac fibrosis, while time intervals and rhythm were unchanged (except for a longer QRS duration in patients with severe fibrosis). All patients with severe fibrosis showed T inversion, ST alteration, or both. With Holter ECG, maximum and minimum heart rate did not differ with fibrosis severity. Patients without fibrotic tissue showed less ventricular premature beats (VPB) (median 5/24h) compared to those with mild (median 11/24h) or severe fibrosis (median 115/24h; P < 0.05, respectively). Fibrosis was a strong predictor of VPB burden (r 2 = 0.5; P < 0.001). During exercise, patients with severe fibrosis had the least increase in systolic blood pressure (sBP) (47 ± 22mmHg vs. 62 ± 25mmHg, P < 0.05) and the lowest maximum heart rate (113 ± 18/min; P < 0.05). Patients with mild fibrosis had a high sBP during exercise (198 ± 37mmHg; P < 0.05). Decreased diastolic blood pressure (>10mmHg) occurred in some patients with no (3/41) or mild fibrosis (3/34) but not in patients with severe fibrosis (0/20; P < 0.01). Our data suggest that cardiac replacement fibrosis is responsible for repolarization abnormalities on resting ECG and increased VPB with Holter ECG. During exercise ECG, advanced cardiomyopathy is characterized by chronotropic incompetence with limitations on blood pressure and heart rate increase.

Heart rate target treatment shortfall in contemporary beta-blocker therapy of heart failure in 446 patients in sinus rhythm

Background: Despite modern aggressive beta-blocker (BB) therapy of patients with heart failure, many do not reach the established heart rate goal of <77 beats per minute (bpm). Methods: We identified 446 consecutive patients in sinus rhythm (with or without pacing) with initial ejection fraction (EF) ≤35% undergoing echocardiograms for heart failure. BB therapy was converted into “bisoprolol equivalents”. Most recent clinic ECG heart rate and EF was recorded. Results: Of 446 patients, (315 male, age 71.4±12yrs), baseline EF was 26±6.5%, with BB used in 86% (6.0±4mg), ACE inhibitors in 56%, angiotensin blockers in 23%, frusemide in 40% (53±38mg), nitrates in 9%, aldosterone antagonists in 24% and ivabradine in 2%. Device therapy was used in 55% (205 ICD±CRT, 42 pacemakers). The average treated heart rate overall was 68.5±12.8 bpm. Target heart rate (<78bpm) was achieved in 345/446 (77%, 63±7bpm), while 101/446 (23%) did not (87±10bpm, p<0.05). Patients who reached target heart rate were more likely to be on beta-blockers (89% vs 70%, X2 p=0.008), with higher average beta-blocker doses (6.4±4.0mg vs 4.7±4.7mg, p<0.05), were older (72±11yrs vs 69±14yrs p=0.01) and had a significantly larger improvement in EF over an average of 1.3 years of treatment (+11% vs +8.5%, p=0.046) than those who did not achieve target. Conclusions: Nearly a quarter of heart failure patients in sinus rhythm have persistent heart rate >77bpm. They are on less beta-blocker, are younger, and achieve less improvement in EF. These patients may benefit from more vigorous heart rate slowing with higher beta blocker dose and ivabradine.

Combined Effects of Vincristine and Quercetin in Reducing Isoproterenol-Induced Cardiac Necrosis in Rats.

Combined effects of vincristine and quercetin in the regulation of isoproterenol (ISO)-induced cardiac necrosis have been evaluated in rats. ISO administration (100mg/kg, s.c., for two consecutive days) increased the levels of serum creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), glutamate pyruvate transaminase (SGPT) and cardiac troponin (cTnT) as well as cardiac lipid peroxidation products (malondialdehyde and lipid hydroperoxides). However, it reduced the activities of superoxide dismutase (SOD), catalase and the glutathione peroxidase and the level of reduced glutathione. It also increased the heart rate and ST-segment elevation in ECG. Pretreatment of vincristine (25μg/kg) or quercetin (10mg/kg) alone for 2weeks ameliorated these cardiotoxic effects partially. However, treatment of both vincristine and quercetin for a similar period reduced the serum CK-MB, LDH, SGPT and cTnT levels near to normal levels in ISO-treated rats. Concomitantly, the test drugs improved the status of antioxidants and decreased the cardiac lipid peroxidation products. Combined treatment of both the drugs also restored the pathological electrocardiographic patterns and reduced the area of myocardial necrosis. Histopathology of heart in ISO-administered rats that received both vincristine and quercetin showed nearly normal myocardium with very little inflammatory infiltration. In conclusion, the present finding appears to be the first one, suggesting a better protection of cardiac tissues by combined treatment of vincristine and quercetin in isoproterenol-induced cardiac toxicity.

Validation of Heart Rate Derived from a Physiological Status Monitor-Embedded Compression Shirt Against Criterion ECG

Firefighters are subject to extreme environments and high physical demands when performing duty-related tasks. Recently, physiological status monitors (PSM) have been embedded into a compression shirt to enable firefighters to measure, visualize, log, and transmit vital metrics such as heart rate (HR) to aid in cardiovascular risk identification and mitigation, thereby attempting to improve the health, fitness, and safety of this population. The purpose of this study was to validate HR recorded by the PSM-embedded compression shirt against a criterion standard laboratory ECG-derived HR when worn concurrently with structural firefighting personal protective equipment (PPE) during four simulated firefighting activities. Ten healthy, college-age men (mean ± SD: age: 21 ± 1 yr; body mass: 91 ± 10 kg; body mass index: 26.9 ± 3.1 kg/m2) completed four tasks that are routinely performed during firefighting operations: outdoor fast-paced walking (FW), treadmill walking (TW), searching/crawling (SC), and ascending/descending stairs (AD). They wore the PSM-embedded compression shirt under structural firefighting PPE. HR was recorded concurrently by the PSM-embedded compression shirt and a portable metabolic measurement system accompanied with a standard 12-lead electrocardiograph that was used to provide criterion measures of HR. For all four tasks combined there was very high correlation of PSM and ECG HR (r > 0.99; SEE 0.84 /min) with a mean difference (bias) of −0.02 /min and limits of agreement of −0.07 to 0.02 /min. For individual tasks, the correlations were also high (r-values = 0.99; SEE 0.81–0.89). The mean bias (limits of agreement) was: FW 0.03 (-0.09 to 0.14); TW 0.04 (−0.05 to 0.12); SC −0.01 (−0.12 to 0.10); AD −0.13 (−0.21 to −0.04) /min. These findings demonstrate that the PSM-embedded compression shirt provides a valid measure of HR during simulated firefighting activities when compared with a standard 12-lead ECG.

PS-103 Heart Rate In Infants At Birth Is Lower Measured By Pulse Oximetry When Compared With Electrocardiography: Abstract PS-103 Table 1

Background and aim Heart rate (HR) is the most important parameter for evaluation of infants at birth. Studies using pulse oximetry (PO) have shown that healthy (pre)term infants can be bradycardic at birth. While HRs measured with PO (HR PO ) and ECG (HR ECG ) have been compared, time after birth was not a factor in the analysis. We compared HR ECG and HR PO at specific time points after birth, hypothesising that a discrepancy may exist immediately after birth. Methods ECG electrodes and a PO sensor were attached as soon as possible after birth in healthy pre (term) infants. PO data with Signal Identification and Quality ECG and HR PO were compared every 30 s from 1–10 min. Results 755 data pairs of 53 patients were analysed. Median (range) gestational age was 36 (27–41) weeks. Data from ECG and PO were acquired from 82 (26) and 99 (33)s after birth. Median HR PO was ECG remained stable at 150–160 bpm (table). Conclusion HR measured by PO is significantly lower compared to ECG, which has important implications for clinical care in the first minutes after birth.

114 Should we Standardise how Heart Rate is Measured?

IntroductionThere is increasing evidence that lowering HR in cardiovascular disease may be beneficial.Recent trials have documented heart rate (HR) using supine ECG and the NICE guideline for heart failure[1,2] suggests...

A Portable ECG Monitor with Low Power Consumption and Small Size Based on AD8232 Chip

This paper design a portable ECG monitor based on mobile phone. Using the single-lead heart rate monitor analog front-end of AD8232 chip produced by ADI co. Ltd., the monitor can measure human ECG signal and heart rate with only two electrode pads placed on chest, and display the ECG signal on the mobile phone via Bluetooth communication in real time. It also can simply measure the heart rate by touching the two electrodes of the monitor directly. The system has many functions like ECG signal analysis, heart rate counting, arrhythmia detection, signal playback, leads off detection, fast recovery ECG. The result shows that the portable ECG monitor is low cost, low power consumption, small size and easy to carry, etc.

Desensitization by Progressive Up-Titration Prevents First-Dose Effects on the Heart: Guinea Pig Study with Ponesimod, a Selective S1P1 Receptor Modulator

Ponesimod, a selective S1P1 receptor modulator, reduces the blood lymphocyte count in all tested species by preventing egress of T and B cells from thymus and peripheral lymphoid organs. In addition, ponesimod transiently affects heart rate and atrioventricular (AV) conduction in humans, effects not observed in mice, rats, and dogs with selective S1P1 receptor modulators, suggesting that the regulation of heart rate and rhythm is species dependent. In the present study, we used conscious guinea pigs implanted with a telemetry device to investigate the effects of single and multiple oral doses of ponesimod on ECG variables, heart rate, and blood pressure. Oral administration of ponesimod did not affect the sinus rate (P rate) but dose-dependently induced AV block type I to III. A single oral dose of 0.1 mg/kg had no effect on ECG variables, while a dose of 3 mg/kg induced AV block type III in all treated guinea pigs. Repeated oral dosing of 1 or 3 mg/kg ponesimod resulted in rapid desensitization, so that the second dose had no or a clearly reduced effect on ECG variables as compared with the first dose. Resensitization of the S1P1 receptor in the heart was concentration dependent. After desensitization had been induced by the first dose of ponesimod, the cardiac system remained desensitized as long as the plasma concentration was ≥75 ng/ml. By using a progressive up-titration regimen, the first-dose effect of ponesimod on heart rate and AV conduction was significantly reduced due to desensitization of the S1P1 receptor. In summary, conscious guinea pigs implanted with a telemetry device represent a useful model to study first-dose effects of S1P1 receptor modulators on heart rate and rhythm. This knowledge was translated to a dosing regimen of ponesimod to be tested in humans to avoid or significantly reduce the first-dose effects.

Altered electrophysiological properties and deranged cardiac autonomic modulation predispose patients to atrial fibrillation after arrested heart operations

Background Advanced Heart Rate (HR) Variability analyses applying non-linear dynamics and chaos theory provide information about derangement of cardiac autonomic modulation predicting ventricular or atrial arrhythmias. Aim of the present study was to determine which high-resolution ECG and non-linear HR dynamics parameters predispose to development of postoperative atrial fibrillation after surgery on the open arrested heart.

Sexual dysfunction in pre-menopausal diabetic women: clinical, metabolic, psychological, cardiovascular, and neurophysiologic correlates

An increased prevalence of female sexual dysfunction (FSD) has been reported in women with diabetes mellitus (DM). Our aim was to evaluate correlates (psychological, cardiovascular, and neurophysiologic) of FSD in DM women without chronic diabetic complications. Female Sexual Function Index (FSFI), Beck Depression Inventory (BDI), Michigan Diabetic Neuropathy Index (DNI), and the symptoms of diabetic neuropathy (SDN) questionnaires, metabolic variables, endothelial vascular function (flow-mediated dilation, FMD), echocardiography, and electromyography were studied. 109 pre-menopausal women (18-50 years) [48 with DM (14 type 1 DM, 34 type 2 DM, duration 12.6 ± 1.91 years), and 61 healthy women] received the above questionnaires; physical activity, smoking habits, parity, BMI, waist circumference, HOMA-IR index, fibrinogen, cholesterol (total, HDL, LDL), triglycerides, HbA1c, high-sensitivity C-reactive protein, total testosterone, and estradiol were measured; echocardiography, assessment of intima-media thickness (IMT), FMD, ECG (heart rate and Qtc, indexes of sympathetic activity), and electromyography were performed. FSFI total score and score for arousal, lubrication, and orgasm domains were lower in DM women than in controls (P < 0.05); DM women had higher BDI, Doppler A wave peak velocity, DNI, and SDN score (P < 0.001 to P < 0.04). Doppler E wave peak velocity, peroneal, posterior tibial and sural nerves conduction velocity and amplitude were lower in diabetic women than in controls (P < 0.05 to P < 0.001). FSFI score was positively correlated with physical activity, Doppler E wave peak velocity, and peroneal nerve amplitude and negatively with BDI, parity, IMT, SDN, and HbA1c (P < 0.05 to P < 0.001). At stepwise regression, SDN score (negatively) and Doppler E wave peak velocity (positively) predicted FSFI score (r = 507, P < 0.001). In conclusion, cardiovascular and neurological impairments are associated with FSD in diabetic women. Follow-up studies are required to evaluate sexual dysfunction as a risk factor for future cardiovascular or neurological events.

Immunadsorption therapy for end stage heart failure due to Duchenne muscular dystrophy

We report about a successful immunadsorption therapy of a boy with end stage heart failure due to Duchenne muscular dystrophy who has little chance to get cardiac transplantation. Prior to this therapy a medical therapy with an angiotensin converting enzyme inhibitor, a low dose betablocker, an aldosterone antagonist, and diuretics failed. In consent with the patient and his parents immunoadsorption therapy employing a protein A column was performed. Due to clinical improvement the betablocker carvedilol could be titrated from 6.25 mg up to 30 mg. In the following 4 month he improves from NYHA class IV to NYHA class II and NT-Pro-BNP levels fell from 5180 pg/ml to 402 pg/ml. The mean heart rate in Holter ECG decreases from 102/min to 68/min and ejection fraction improved from 25% to 30%. The boy began to walk without any support and was able to visit school. This clinical improvement now holds on for 2 years.

Etanercept Induces Low QRS Voltage and Autonomic Dysfunction in Mice with Experimental Chagas Disease

BackgroundChagas disease is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. Chagasic cardiomyopathy is characterized by disorders of autonomic regulation and action potential conduction in the acute and chronic phases of infection. Although tumor necrosis factor alpha (TNF-α) has been linked to cardiomyopathy in experimental models and in patients with Chagas disease, other reports suggest that TNF-α may exert anti-parasitic actions during the acute phase of infection. ObjectivesThis study aimed to determine the effects of a soluble TNF-α blocker, etanercept, on electrocardiographic parameters in the acute phase of experimental infection with Trypanosoma cruzi. MethodsElectrocardiograms were obtained from untreated infected mice and infected mice who were treated with etanercept 7 days after infection. ECG wave and heart rate variability parameters were determined using Chart for Windows. ResultsEtanercept treatment resulted in a low QRS voltage and decreased heart rate variability compared with no treatment. However, the treated mice exhibited a delay in the fall of the survival curve during the acute phase. ConclusionThe results of this study suggest that although etanercept treatment promotes survival in mice infected with a virulent T. cruzi strain, TNF-α blockade generates a low voltage complex and autonomic dysfunction during the acute phase of infection. These findings indicate that mortality during the acute phase can be attributed to a systemic inflammatory response rather than cardiac dysfunction.

Relationships between QT interval and heart rate variability at rest and the covariates in healthy young adults

To clarify the links between ECG QT-related parameters and heart rate variability (HRV) and the covariates possibly distorting them, the averaged RR and QT intervals in a single lead ECG were measured for 64 male and 86 female subjects aged 18-26. The QT index, defined by Rautaharju et al., in the young adults was not significantly related to any HRV parameters nor heart rate, but the Bazett's corrected QT (QTc) interval was associated negatively with the parasympathetic activity and positively with heart rate. No significant differences in the QTc interval, QT index or heart rate were seen between the men and women, but they significantly differed between both sexes after adjustment for possible covariates such as age and body mass index (BMI). Significant sex differences in parasympathetic parameters of the HRV were unchanged before and after the adjustment, but significant differences observed in the unadjusted sympathetic parameters disappeared after adjusting for covariates. Age, BMI and body fat percentage also were significant covariates affecting these ECG parameters. Consequently, QT index, unaffected by heart rate and HRV parameters, appears to be a more useful indicator than the QTc interval. Instead, the QT index and HRV parameters are recommended to be simultaneously measured in epidemiological research because they are probably complementary in assessing autonomic nervous function. Also, these parameters should be analyzed in men and women separately.

Clot burden score in the evaluation of right ventricular dysfunction in acute pulmonary embolism: Quantifying the cause and clarifying the consequences

IntroductionPulmonary angiography by computed tomography (CT) is the method of choice for the detection of acute pulmonary embolism (PE). Studies have shown that the severity of PE can be estimated by clot burden scores. ObjectiveTo evaluate the correlation between an angiographic clot burden score (Qanadli score–QS) and parameters of right ventricular dysfunction (RVD) in patients admitted for PE. MethodsWe performed a retrospective study of 107 patients (60% female) admitted to an intensive care unit for PE (intermediate/high risk) between January 1, 2007 and September 30, 2011. Images from 16-slice multidetector CT angiography were reviewed in 102 patients and the QS calculated. Based on a cut-off of 18 points established by ROC curve analysis, two groups were formed (A<18 points vs. B≥18 points) and the clinical, laboratory, ECG, echocardiographic and CT angiography parameters were compared. The statistical analysis was performed using SPSS. ResultsThe overall mean age was 61.4 years. With regard to symptoms at admission, there was a greater prevalence in group B of fatigue, chest pain and syncope (p=0.017), with higher Geneva and Wells scores and shock index.In terms of ECG parameters, heart rate and percentage of right bundle branch block, T-wave inversion (V1–V3) and S1Q3T3 pattern (p=0.034) were higher in group B, as was the ECG score (p=0.009).Laboratory tests revealed that group B had higher troponin and d-dimers, with lower creatinine clearance by the MDRD formula (p=0.020) and PO2/FiO2 ratio. Echocardiography showed higher pulmonary artery systolic pressure in group B, and CT angiography revealed larger right ventricular (RV) diameters and higher RV/LV ratio (p=0.002), and greater superior vena cava, azygos vein and coronary sinus diameters in this group. Pulmonary artery (PA) diameter and the PA/aorta ratio were similar. Interventricular septal bowing and reflux of contrast into the inferior vena cava (p=0.001) were greater in group B, and QS>18 was an independent predictor of RVD (RV/LV ratio>1) (OR: 10.85; p<0.001) (area under the curve on ROC analysis: 0.79; p<0.001).The percentage of patients receiving fibrinolytic treatment was higher in group B (p=0.045), and in-hospital mortality was similar in both groups (overall 4.9%). ConclusionsQS>18 points proved to be an independent predictor of RVD in PE, and correlated linearly with variables associated with higher morbidity and mortality.

O valor da carga embólica na avaliação de disfunção ventricular direita no tromboembolismo pulmonar agudo: quantificando a causa e clarificando as consequências

IntroductionPulmonary angiography by computed tomography (CT) is the method of choice for the detection of acute pulmonary embolism (PE). Studies have shown that the severity of PE can be estimated by clot burden scores. ObjectiveTo evaluate the correlation between an angiographic clot burden score (Qanadli score - QS) and parameters of right ventricular dysfunction (RVD) in patients admitted for PE. MethodsWe performed a retrospective study of 107 patients (60% female) admitted to an intensive care unit for PE (intermediate/high risk) between January 1, 2007 and September 30, 2011. Images from 16-slice multidetector CT angiography were reviewed in 102 patients and the QS calculated. Based on a cut-off of 18 points established by ROC curve analysis, two groups were formed (A<18 points vs. B ≥18 points) and the clinical, laboratory, ECG, echocardiographic and CT angiography parameters were compared. The statistical analysis was performed using SPSS. ResultsThe overall mean age was 61.4 years. With regard to symptoms at admission, there was a greater prevalence in group B of fatigue, chest pain and syncope (p=0.017), with higher Geneva and Wells scores and shock index.In terms of ECG parameters, heart rate and percentage of right bundle branch block, T-wave inversion (V1-V3) and S1Q3T3 pattern (p=0.034) were higher in group B, as was the ECG score (p=0.009).Laboratory tests revealed that group B had higher troponin and d-dimers, with lower creatinine clearance by the MDRD formula (p=0.020) and PO2/FiO2 ratio. Echocardiography showed higher pulmonary artery systolic pressure in group B, and CT angiography revealed larger right ventricular (RV) diameters and higher RV/LV ratio (p=0.002), and greater superior vena cava, azygos vein and coronary sinus diameters in this group. Pulmonary artery (PA) diameter and the PA/aorta ratio were similar. Interventricular septal bowing and reflux of contrast into the inferior vena cava (p=0.001) were greater in group B, and QS>18 was an independent predictor of RVD (RV/LV ratio>1) (OR: 10.85; p<0.001) (area under the curve on ROC analysis: 0.79; p<0.001). The percentage of patients receiving fibrinolytic treatment was higher in group B (p=0.045), and in-hospital mortality was similar in both groups (overall 4.9%). ConclusionsQS >18 points proved to be an independent predictor of RVD in PE, and correlated linearly with variables associated with higher morbidity and mortality.