Electrocardiographic detection of right ventricular pressure overload in patients with suspected pulmonary hypertension

The Utility of a Resting Electrocardiogram (ECG-PH Index) in Evaluating the Efficacy of Pulmonary Endarterectomy in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

The ECG-PH index (PH-ECG score) has been proposed as a valuable ECG-derived method of evaluating the effectiveness of balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH). Pulmonary endarterectomy (PEA) is the main form of therapy for CTEPH with a proximal clot location. The objective of this study was to assess the clinical utility of a resting electrocardiogram (ECG-PH index) in assessing the effectiveness of PEA in CTEPH patients.

METHODS

The retrospective analysis included 73 patients who underwent PEA. Their ECG-PH index values were calculated using four ECG parameters: R-wave amplitude V1 + S-wave amplitude V5/V6 > 10.5 mm, QRS-wave axis > 110 degrees, R-wave amplitude V1 > S-wave amplitude V1, and SIQIII pattern. PH-ECG scores were assessed after a median time of 13 months (IQR: 8-31 months) had passed since the PEA procedures.

RESULTS

The current analysis documented that ECG-PH index = 0 is a good reflection of mPAP < 25mmHg (sensitivity 76.1%; specificity 66.7%; positive predictive value 79.5%; negative predictive value 62.1%) or mPAP ≤ 20 mmHg (sensitivity 69.6%; specificity 70.6%; positive predictive value 88.6%; negative predictive value 41.4%) after PEA. The values of the area under the ROC curve for ECG-PH index were 0.772 (95% CI: 0.676-0.867) and 0.743 (95% CI: 0.637-0.849) for the mPAP < 25 mmHg and mPAP ≤ 20 mmHg patient groups, respectively.

CONCLUSION

The ECG-PH index may be useful for monitoring the haemodynamic effect of PEA in CTEPH patients.

Intra-Individual Comparison of Sinus and Ectopic Beats Probing the Ventricular Gradient's Activation Dependence

Wilson assumed that the ventricular gradient (VG) is independent of the ventricular activation order. This paradigm has often been refuted and was never convincingly corroborated. We sought to validate Wilson's concept by intra-individual comparison of the VG of sinus beats and ectopic beats, thus assessing the effects of both altered ventricular conduction (caused by the ectopic focus) and restitution (caused by ectopic prematurity). We studied standard diagnostic ECGs of 118 patients with accidental extrasystoles: normally conducted supraventricular ectopic beats (SN, N = 6) and aberrantly conducted supraventricular ectopic beats (SA, N = 20) or ventricular ectopic beats (V, N = 92). In each patient, we computed the VG vectors of the predominant beat, VGp→, of the ectopic beat, VGe→, and of the VG difference vector, ΔVGep→, and compared their sizes. VGe→ of the SA and V ectopic beats were significantly larger than VGp→ (53.7 ± 25.0 vs. 47.8 ± 24.6 mV∙ms, respectively; p < 0.001). ΔVGep→ were three times larger than the difference of VGe→ and VGp→ (19.94 ± 9.76 vs. 5.94 mV∙ms, respectively), demonstrating differences in the VGp→ and VGe→ spatial directions. The amount of ectopic prematurity was not correlated with ΔVGep→, although the larger VG difference vectors were observed for the more premature (<80%) extrasystoles. Electrical restitution properties and electrotonic interactions likely explain our findings. We conclude that the concept of a conduction-independent VG should be tested at equal heart rates and without including premature extrasystoles.

The spatial ventricular gradient is associated with adverse outcomes in acute pulmonary embolism

BACKGROUND

The spatial ventricular gradient (SVG) is a vectorcardiographic measurement that reflects cardiac loading conditions via electromechanical coupling.

OBJECTIVES

We hypothesized that the SVG is correlated with right ventricular (RV) strain and is prognostic of adverse events in patients with acute pulmonary embolism (PE).

METHODS

Retrospective, single-center study of patients with acute PE. Electrocardiogram (ECG), imaging, and outcome data were obtained. SVG components were regressed on tricuspid annular plane systolic excursion (TAPSE), qualitative RV dysfunction, and RV/left ventricular (LV) ratio. Odds of adverse outcomes (30-day mortality, vasopressor requirement, or advanced therapy) after PE were regressed on demographics, RV/LV ratios, traditional ECG signs of RV dysfunction, and SVG components using a logit model.

RESULTS

ECGs from 317 patients (48% male, age 63.1 ± 16.6 years) with acute PE were analyzed; 36 patients (11.4%) experienced an adverse event. Worse RV hypokinesis, larger RV/LV ratio, and smaller TAPSE were associated with smaller SVG X and Y components, larger SVG Z components, and smaller SVG vector magnitude (p < .001 for all). In multivariable logistic regression, odds of adverse events after PE decreased with increasing SVG magnitude and TAPSE (OR 0.32 and 0.54 per standard deviation increase; p = .03 and p = .004, respectively). Receiver operating characteristic (ROC) analysis showed that, when combined with imaging, replacing traditional ECG criteria with the SVG significantly improved the area under the ROC from 0.70 to 0.77 (p = .01).

CONCLUSION

The SVG is correlated with RV dysfunction and adverse outcomes in acute PE and has a better prognostic value than traditional ECG markers.

Diagnostic efficacy of ECG-derived ventricular gradient for the detection of chronic thromboembolic pulmonary hypertension in patients with acute pulmonary embolism

INTRODUCTION

Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide [NTproBNP] test) can rule out CTEPH in pulmonary embolism (PE) patients with persistent dyspnea (InShape II algorithm). Increased pulmonary pressure may also be identified using automated ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO).

METHOD

A predefined analysis of the InShape II study was performed. The diagnostic performance of the VG-RVPO for the detection of CTEPH and the incremental diagnostic value of the VG-RVPO as new rule-out criteria in the InShape II algorithm were evaluated.

RESULTS

60 patients were included; 5 (8.3%) were ultimately diagnosed with CTEPH. The mean baseline VG-RVPO (at time of PE diagnosis) was -18.12 mV·ms for CTEPH patients and - 21.57 mV·ms for non-CTEPH patients (mean difference 3.46 mV·ms [95%CI -29.03 to 35.94]). The VG-RVPO (after 3-6 months follow-up) normalized in patients with and without CTEPH, without a clear between-group difference (mean Δ VG-RVPO of -8.68 and - 8.42 mV·ms respectively; mean difference of -0.25 mV·ms, [95%CI -12.94 to 12.44]). The overall predictive accuracy of baseline VG-RVPO, follow-up RVPO and Δ VG-RVPO for CTEPH was moderate to poor (ROC AUC 0.611, 0.514 and 0.539, respectively). Up to 76% of the required echocardiograms could have been avoided with VG-RVPO criteria replacing the InShape II rule-out criteria, however at cost of missing up to 80% of the CTEPH diagnoses.

CONCLUSION

We could not demonstrate (additional) diagnostic value of VG-RVPO as standalone test or as on top of the InShape II algorithm.

The value of ventricular gradient for predicting pulmonary hypertension and mortality in hemodialysis patients

Pulmonary hypertension (PHT) is associated with increased mortality in hemodialysis (HD) patients. The ventricular gradient optimized for right ventricular pressure overload (VG-RVPO) is sensitive to early changes in right ventricular overload. The study aimed to assess the ability of the VG-RVPO to detect PHT and predict all-cause and cardiac mortality in HD patients. 265 selected HD patients were enrolled. Clinical, biochemical, electrocardiographic, and echocardiographic parameters were evaluated. Patients were divided into normal and abnormal VG-RVPO groups, and were followed-up for 3 years. Abnormal VG-RVPO patients were more likely to be at high or intermediate risk for PHT, were older, had longer HD vintage, higher prevalence of myocardial infarction, higher parathormone levels, shorter pulmonary flow acceleration time, lower left ventricular ejection fraction, higher values of left atrial volume index, left ventricular mass index, and peak tricuspid regurgitant velocity. Both all-cause and CV mortality were higher in abnormal VG-RVPO group. In multivariate Cox analysis, VG-RVPO remained an independent and strong predictor of all-cause and CV mortality. In HD patients, abnormal VG-RVPO not only predicts PHT, but also all-cause and CV mortality.

Lack of diagnostic utility of the ECG-derived ventricular gradient in patients with suspected acute pulmonary embolism

INTRODUCTION

The YEARS algorithm was successfully developed to reduce the number of computed tomography pulmonary angiography (CTPA) investigations in the diagnostic management of patients with suspected pulmonary embolism (PE), although half of patients still needed to be referred for CTPA. We hypothesized that ECG derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO), an easy to use tool for detecting PE-induced pulmonary hypertension (PH), may further improve the efficiency of the YEARS algorithm.

METHODS

In this post-hoc analysis of the Years study, ECGs of 479 patients with suspected PE managed according to the YEARS algorithm were available for analysis. The diagnostic performance of VG-RVPO was assessed and likelihood ratios were calculated.

RESULTS

PE was diagnosed in 88 patients (18%). In patients with confirmed PE, 34% had an abnormal VG-RVPO versus 24% of those without PE (odds ratio 1.6; 95%CI 0.94-2.6). The mean VG-RVPO was -22 ± 13 and did not differ between the two patient groups (-22 versus -20; mean difference - 2, 95% CI -4.8 to 1.3). The sensitivity of VG-RVPO for PE was 24% (95%CI 34-45), the specificity 76% (95%CI 71-80) and the c-statistic 0.45 (95% CI 0.38-0.51). When combined with the YEARS algorithm, the likelihood ratios of VG-RVPO remained close to 1.0. Ruling out PE in patients with an indication for CTPA based on a normal VG-RVPO would have resulted in 58 missed cases.

CONCLUSIONS

The VG-RVPO has no diagnostic value for suspected acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm.

CONDENSED ABSTRACT

This post-hoc analysis of the YEARS study failed to demonstrate incremental diagnostic value of VG-RVPO for acute PE, either as stand-alone diagnostic test or combined with the YEARS algorithm. Nevertheless, the role of VG-RVPO recorded on admission could potentially be valuable in the risk stratification of PE during hospitalization, although this remains to be studied.

Comparison of the integral indices of the vectorcardiogram with the data of echocardiography in patients with idiopathic and chronic thromboembolic pulmonary hypertension

AIM

The aim of the work is to compare vectorcardiographic (VCG) variables - spatial QRS-T angle and electrocardiographic ventricular gradient (VG) with echocardiography (EchoCG) data in patients with idiopathic pulmonary hypertension (IPH) and chronic thromboembolic pulmonary hypertension (CTEPH).

MATERIALS AND METHODS

In 40 patients with IPH and 40 patients with CTEPH at the age of 45±12 years, systolic pulmonary artery pressure (SPAP); the sizes of heart chambers, parameters of RV systolic and diastolic function were evaluated with EchoCG. The QRS-T and VG angles were calculated on the VCG, derived from 12-lead digital ECG.

RESULTS

In all patients SPAP was greater than 40 mm Hg (mean 83±18 mm Hg), EchoCG data indicated hypertrophy and dilatation of RV, its systolic and diastolic function; dilatation of the right atrium (RA). Prognostically unfavorable changes in EchoCG were observed: the presence of pericardial effusion in 35 (44%) patients, RA area greater than 26 cm2 in 18 (23%) patients; TAPSE less than 1.5 cm in 37 (46%) patients. EchoCG and VCG variables had statistically significant differences in patients with III-IV functional class in comparison with I-II functional class. Statistically significant moderate correlations between VCG and EchoCG variables were revealed. VCG variables allowed to separate patient groups with the presence and absence of prognostically unfavorable changes in EchoCG with sensitivity from 54 to 78% and specificity from 66 to 87%.

CONCLUSION

In patients with IPH and CTEPH, changes of QRS-T angle and VG correlate with SPAP, the size of RV and RA, parameters of RV systolic and diastolic function. The possibility of the use of QRS-T angle and VG for the detection of patients with prognostically unfavorable echocardiographic changes in the general group of patients with IPH and CTEPH has been shown.

Electrical remodeling after percutaneous atrial septal defect closure in pediatric and adult patients

BACKGROUND

Several studies have reported changes in electrocardiographic variables after atrial septal defect (ASD) closure. However no temporal electro-and vectorcardiographic changes have been described from acute to long-term follow-up at different ages. We aimed to study electrical remodeling after percutaneous ASD closure in pediatric and adult patients.

METHODS

ECGs of 69 children and 75 adults (median age 6 [IQR 4-11] years and 45 [IQR 33-54] years, respectively) were retrospectively selected before percutaneous ASD closure and at acute (1-7 days), intermediate (4-14 weeks) and late (6-18 months) follow-up. Apart from electrocardiographic variables, spatial QRS-T angle and ventricular gradient (VG) were derived from mathematically-synthesized vectorcardiograms.

RESULTS

In both pediatric and adult patients, the heart rate decreased immediately post-closure, which persisted to late follow-up. The P-wave amplitude also decreased acutely post-closure, but remained unchanged at later follow-up. The PQ duration shortened immediately in children and at intermediate follow-up in adults. The QRS duration and QTc interval decreased at intermediate-term follow-up in both children and adults. In both groups the spatial QRS-T angle decreased at late follow-up. The VG magnitude increased at intermediate follow-up in children and at late follow-up in adults, after an initial decrease in children.

CONCLUSION

In both pediatric and adult ASD patients, electrocardiographic changes mainly occurred directly after ASD closure except for shortening of QRS duration and QTc interval, which occurred at later follow-up. Adults also showed late changes in PQ duration. At 6-to-18 month post-closure, the spatial QRS-T angle decreased, reflecting increased electrocardiographic concordance. The initial acute decrease in VG in children, which was followed by a significant increase, may be the effect of action potential duration dynamics directly after percutaneous ASD closure.

Improvement in the electrocardiograms associated with right ventricular hypertrophy after balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension

Background

Balloon pulmonary angioplasty (BPA) is a treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Methods and results

In 60 patients with CTEPH, we examined the hemodynamic data before and after BPA. In addition, the sequential ECG findings for right ventricular hypertrophy (RVH) were assessed. The mean pulmonary arterial pressure (mPAP) decreased from 38 ± 11 to 20 ± 4 mm Hg (p < 0.05). The ROC analysis showed that the S waves in V5, R waves in V1 + S waves in V5, S waves in I, and QRS axis were significant predictors of an mPAP ≧ 30 mm Hg (AUC > 0.75, p < 0.01). The predictive values for the mPAP before the BPA were the S and R waves in lead V6, and P waves in lead II (33.417 + 0.078 × P in II − 0.10 × R in V6 + 0.012 × S in V6). The change in the mPAP (ΔmPAP) correlated with the change in the amplitudes of the ECGs: ΔS wave in lead I (R = 0.544, p < 0.001), ΔR in V1 + S in V5 (R = 0.476, p < 0.001), and ΔP wave in II (R = 0.511, p < 0.001). At 6 months of follow-up, the improvement in an R in V1 + S in V5 of ≧10 mm implied a better functional status.

Conclusion

BPA therapy reduced the pulmonary arterial pressure in patients with CTEPH and was associated with an improvement in the ECG findings related to RVH.

Normal values of the ventricular gradient and QRS-T angle, derived from the pediatric electrocardiogram

BACKGROUND

Normal values of the mathematically-synthesized vectorcardiogram (VCG) are lacking for children. Therefore, the objective of this study was to assess normal values of the pediatric synthesized VCG (spatial QRS-T angle [SA] and ventricular gradient [VG]).

METHODS

Electrocardiograms (ECGs) of 1263 subjects (0-24 years) with a normal heart were retrospectively selected. VCGs were synthesized by the Kors matrix. Normal values (presented as 2nd and 98th percentiles) were assessed by quantile regression with smoothing by splines.

RESULTS

Our results show that heart rate decreased over age, QRS duration increased and QTc interval remained constant. The SA initially decreased and increased again from the age of 8 years. The VG magnitude was relatively stable until the age of 2 years, after which it increased.

CONCLUSION

Normal values of the pediatric ECG and VCG (VG and SA) were established. These normal values could be important for future studies using VG and SA for risk stratification in heart disease in children.

ECG-derived spatial QRS-T angle is associated with ICD implantation, mortality and heart failure admissions in patients with LV systolic dysfunction

Background

Increased spatial QRS-T angle has been shown to predict appropriate implantable cardioverter defibrilIator (ICD) therapy in patients with left ventricular systolic dysfunction (LVSD). We performed a retrospective cohort study in patients with left ventricular ejection fraction (LVEF) 31–40% to assess the relationship between the spatial QRS-T angle and other advanced ECG (A-ECG) as well as echocardiographic metadata, with all-cause mortality or ICD implantation for secondary prevention.

Methods

534 patients ≤75 years of age with LVEF 31–40% were identified through an echocardiography reporting database. Digital 12-lead ECGs were retrospectively matched to 295 of these patients, for whom echocardiographic and A-ECG metadata were then generated. Data mining was applied to discover novel ECG and echocardiographic markers of risk. Machine learning was used to develop a model to predict possible outcomes.

Results

49 patients (17%) had events, defined as either mortality (n = 16) or ICD implantation for secondary prevention (n = 33). 72 parameters (58 A-ECG, 14 echocardiographic) were univariately different (p<0.05) in those with vs. without events. After adjustment for multiplicity, 24 A-ECG parameters and 3 echocardiographic parameters remained different (p<2x10^-3). These included the posterior-to-leftward QRS loop ratio from the derived vectorcardiographic horizontal plane (previously associated with pulmonary artery pressure, p = 2x10^-6); spatial mean QRS-T angle (134 vs. 112°, p = 1.6x10^-4); various repolarisation vectors; and a previously described 5-parameter A-ECG score for LVSD (p = 4x10^-6) that also correlated with echocardiographic global longitudinal strain (R² = - 0.51, P < 0.0001). A spatial QRS-T angle >110° had an adjusted HR of 3.4 (95% CI 1.6 to 7.4) for secondary ICD implantation or all-cause death and adjusted HR of 4.1 (95% CI 1.2 to 13.9) for future heart failure admission. There was a loss of complexity between A-ECG and echocardiographic variables with an increasing degree of disease.

Conclusion

Spatial QRS-T angle >110° was strongly associated with arrhythmic events and all-cause death. Deep analysis of global ECG and echocardiographic metadata revealed underlying relationships, which otherwise would not have been appreciated. Delivered at scale such techniques may prove useful in clinical decision making in the future.

The comparative relationships between locations of the papillary muscles and electrophysiologic QRS axis in patients with atrioventricular septal defect and common as opposed to separate orifices in the valve guarding the common atrioventricular junction

BACKGROUND

Knowledge regarding factors that influence deviation of the QRS axis is important when seeking to differentiate between physiological and pathological changes. We hypothesised that, in contrast to those patients with an atrioventricular septal defect and common atrioventricular junction permitting only atrial shunting, those associated with ventricular shunting would show no relationship between the positions of the papillary muscles and the degree of the leftward deviation of the QRS axis.

METHODS

We compared the positions of endocardial origin of the papillary muscles, and the frontal plane QRS axis, in patients with atrioventricular septal defects and common atrioventricular junction permitting exclusively atrial as opposed to atrial and ventricular shunting.

RESULTS

We analysed 18 patients with atrial and ventricular shunting and 23 patients with exclusively atrial shunting. The correlation coefficient between the ratio of distances of the papillary muscles from the mid-septum and the amount of leftward deviation in the frontal plane QRS axis was 0.1 (p=0.4) in those with ventricular shunting and 0.26 (p=0.01) in those with exclusively atrial shunting.

CONCLUSIONS

In contrast to patients with the so-called primum form of atrioventricular septal defect, in whom the locations of the papillary muscles correlate with the degree of QRS axis, such relationships are lacking in patients with defects permitting both atrial and ventricular shunting. It may be, therefore, that the presence of ventricular shunting and/or their younger age causes pressure overload, which negates the leftward QRS forces caused by the abnormally positioned papillary muscles.

Changes in surface electrocardiogram in patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary endarterectomy. Correlations with hemodynamic and echocardiographic improvements after surgery

BACKGROUND

The aim of the present study was to evaluate the changes of electrocardiographic (ECG) markers of right ventricular (RV) hypertrophy/overload in patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing pulmonary endarterectomy (PEA).

METHODS AND RESULTS

We evaluated 99 CTEPH patients who underwent PEA. P wave amplitude in DII, R wave amplitude in V1 and the number of patients with negative T wave in V1-V3 decreased significantly at 1month after surgery with no further change at 1year, in parallel with the rapid improvement in right heart hemodynamics. S wave amplitude in V1, R:S wave ratio in lead V6 and prevalence of SIQIII pattern improved significantly at 1year, in parallel with the progressive reverse remodeling of the right ventricle at echocardiography.

CONCLUSIONS

The study shows that some of the ECG markers of RV hypertrophy/overload better reflect RV hemodynamic overload while others better reflect the pathologic remodeling of the right ventricle.

Electrocardiographic detection of pulmonary hypertension in patients with systemic sclerosis using the ventricular gradient

BACKGROUND

Pulmonary hypertension (PH) is a leading cause of death in systemic sclerosis (SSc) patients. The current study assessed the ability of the ECG-derived ventricular gradient (VG-RVPO) to detect PH and predict all-cause mortality in PH patients with subtypes of SSc differing in the extent of multi-organ involvement.

METHODS

ECGs were obtained from 196 patients with limited and 77 patients with diffuse SSc included from our screening programme on cardiac complications. The association of the VG-RVPO with (1) the presence of PH, (2) conventional screening parameters and (3) survival in PH patients was assessed.

RESULTS

In limited SSc patients an elevated VG-RVPO corresponded with the presence of PH (-5±12 mV.ms vs -22±16 mV.ms, P<0.01), correlated significantly with conventional screening parameters and had a better diagnostic performance than the presence of a right heart axis (AUC 0.81 vs 0.60; P=0.04). These differences were not observed in patients with diffuse SSc. An elevated VG-RVPO was associated with decreased survival in all SSc patients with PH (3 year survival 30% vs 64%, P=0.02).

CONCLUSION

An elevated VG-RVPO is associated with PH in limited SSc patients and with decreased survival in all SSc patients with PH.

Vectorcardiographic diagnostic & prognostic information derived from the 12-lead electrocardiogram: Historical review and clinical perspective

In the course of time, electrocardiography has assumed several modalities with varying electrode numbers, electrode positions and lead systems. 12-lead electrocardiography and 3-lead vectorcardiography have become particularly popular. These modalities developed in parallel through the mid-twentieth century. In the same time interval, the physical concepts underlying electrocardiography were defined and worked out. In particular, the vector concept (heart vector, lead vector, volume conductor) appeared to be essential to understanding the manifestations of electrical heart activity, both in the 12-lead electrocardiogram (ECG) and in the 3-lead vectorcardiogram (VCG). Not universally appreciated in the clinic, the vectorcardiogram, and with it the vector concept, went out of use. A revival of vectorcardiography started in the 90's, when VCGs were mathematically synthesized from standard 12-lead ECGs. This facilitated combined electrocardiography and vectorcardiography without the need for a special recording system. This paper gives an overview of these historical developments, elaborates on the vector concept and seeks to define where VCG analysis/interpretation can add diagnostic/prognostic value to conventional 12-lead ECG analysis.