Safety of hyperbaric oxygen therapy in patients with heart failure: A retrospective cohort study.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) has several hemodynamic effects including increases in afterload (due to vasoconstriction) and decreases in cardiac output. This, along with rare reports of pulmonary edema during emergency treatment, has led providers to consider HBOT relatively contraindicated in patients with reduced left ventricular ejection fraction (LVEF). However, there is limited evidence regarding the safety of elective HBOT in patients with heart failure (HF), and no existing reports of complications among patients with HF and preserved LVEF. We aimed to retrospectively review patients with preexisting diagnoses of HF who underwent elective HBOT, to analyze HBOT-related acute HF complications. METHODS: Research Ethics Board approvals were received to retrospectively review patient charts. Patients with a history of HF with either preserved ejection fraction (HFpEF), mid-range ejection fraction (HFmEF), or reduced ejection fraction (HFrEF) who underwent elective HBOT at two Hyperbaric Centers (Toronto General Hospital, Rouge Valley Hyperbaric Medical Centre) between June 2018 and December 2020 were reviewed. RESULTS: Twenty-three patients with a history of HF underwent HBOT, completing an average of 39 (range 6-62) consecutive sessions at 2.0 atmospheres absolute (ATA) (n = 11) or at 2.4 ATA (n = 12); only two patients received fewer than 10 sessions. Thirteen patients had HFpEF (mean LVEF 55 ± 7%), and seven patients had HFrEF (mean LVEF 35 ± 8%) as well as concomitantly decreased right ventricle function (n = 5), moderate/severe tricuspid regurgitation (n = 3), or pulmonary hypertension (n = 5). The remaining three patients had HFmEF (mean LVEF 44 ± 4%). All but one patient was receiving fluid balance therapy either with loop diuretics or dialysis. Twenty-one patients completed HBOT without complications. We observed symptoms consistent with HBOT-related HF exacerbation in two patients. One patient with HFrEF (LVEF 24%) developed dyspnea attributed to pulmonary edema after the fourth treatment, and later admitted to voluntarily holding his diuretics before the session. He was managed with increased oral diuretics as an outpatient, and ultimately completed a course of 33 HBOT sessions uneventfully. Another patient with HFpEF (LVEF 64%) developed dyspnea and desaturation after six sessions, requiring hospital admission. Acute coronary ischemia and pulmonary embolism were ruled out, and an elevated BNP and normal LVEF on echocardiogram confirmed a diagnosis of pulmonary edema in the context of HFpEF. Symptoms subsided after diuretic treatment and the patient was discharged home in stable condition, but elected not to resume HBOT. CONCLUSIONS: Patients with HF, including HFpEF, may develop HF symptoms during HBOT and warrant ongoing surveillance. However, these patients can receive HBOT safely after optimization of HF therapy and fluid restriction.

Assessment of Severity of Long QT Syndrome Phenotype and Risk of Fetal Death.

BACKGROUND: It has been postulated that long QT syndrome (LQTS) can cause fetal loss through putative adverse effects of the channelopathy on placenta and myometrial function. The authors aimed to describe the fetal death rate in a population of pregnant women with long QT syndrome and investigate whether women with more severe phenotype had worse fetal outcomes. METHODS AND RESULTS: The authors retrospectively evaluated fetal outcomes of 64 pregnancies from 23 women with long QT syndrome followed during pregnancy in a tertiary pregnancy and heart disease program. Thirteen of 64 pregnancies (20%) resulted in a fetal loss, 12 miscarriages (19%), and 1 stillbirth (1.6%). Baseline maternal characteristics, including age and use of ß-blockers, did not differ between women who experienced a fetal death or not. Maternal corrected QT interval (QTc) was significantly longer in pregnancies that resulted in fetal death compared with live births (median, 518 ms [interquartile range (IQR), 482-519 ms] versus 479 ms [IQR, 454-496 ms], P<0.001). Mothers treated with ß-blockers had babies born at term with lower birth weight compared with untreated women (2973±298 g versus 3470±338 g, P=0.002). In addition, the birth weight of babies born at term to treated women with QTc >500 ms was significantly lower compared with women with QTc <500 ms (2783±283 g versus 3084±256 g, P=0.029). CONCLUSIONS: Women with long QT syndrome with more severe phenotypes have a higher incidence of fetal death. Maternal QTc is longer in pregnancies that result in fetal loss, and the birth weight of babies born to patients taking ß-blockers with a QTc >500 ms is lower, suggesting that patients with more marked phenotype may experience worse fetal outcomes.

Incidence and Clinical Predictors of Early and Late Complications of Implantable Cardioverter-Defibrillators in Adults With Congenital Heart Disease.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) has been proven to improve survival in adults with congenital heart disease (ACHD), but it is associated with a high rate of complications. We aimed to quantify the incidence of early (≤ 3 months; ECs) and late (> 3 months; LCs) complications in ACHD patients implanted with an ICD and to identify their clinical predictors. METHODS: We retrospectively reviewed 207 patients who had ICD follow-up at Toronto General Hospital from 1996 to 2019. RESULTS: The most common diagnoses were tetralogy of Fallot (32.4%), dextro-transposition of the great arteries (17.9%), and congenital corrected transposition of the great arteries (13%). No intraprocedural complications were observed. Median follow-up was 3.4 years (IQR 0.1-23). 24 patients (12%) developed EC (4 hematomas, 20 lead dislodgements). A total of 56 LCs occurred (46% lead failure, 21% infection, 11% prophylactic lead extraction, 9% neurologic pain, 9% erosion, 4% other) with an incidence rate of LCs of 18% per 5 person-years. Anatomic complexity (odds ratio 2.9; P = 0.02) and cardiac resynchronization therapy defibrillator implant (odds ratio 2.5; P = 0.04) were associated with ECs. Survival rates free from LCs were 92%, 86%, and 65%, respectively, after 1, 5, and 10 years. Presence of legacy leads (hazard ratio 2.9; P = 0.006) and subpulmonary ejection fraction (5% increase, hazard ratio 1.35; P = 0.031) were associated with LCs. CONCLUSIONS: ACHD patients at risk of sudden cardiac death continue to benefit from newer device technology. However, these patients, particularly those with greater anatomic and device complexity, remain at increased risk of developing complications over their lifetime. Given the life expectancy of this population, careful consideration needs to be given when a device for primary prevention is being contemplated.

Ebstein's Anomaly: How to Identify Intracardiac Structures When Electrical Signals Do Not Match the Anatomy.

In patients with Ebstein's anomaly, the distorted anatomy with discordance between the true atrioventricular (AV) groove and the tricuspid valve poses many challenges to the electrophysiologist. Intracardiac echocardiography is a recent tool that allows visualization of the displaced tricuspid valve, the true AV groove, and the atrialized right ventricle. We present a 3-dimensional electroanatomic map built using intracardiac echocardiography and the CARTOSOUND® module (Biosense Webster, Diamond Bar, CA, USA) in one such patient who underwent ablation of a right-sided mid-septal accessory pathway.

The Role of Ablation in Prevention of Recurrent Implantable Cardioverter Defibrillator Shocks in Patients With Tetralogy of Fallot.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) are effective in preventing arrhythmic sudden cardiac death in patients with tetralogy of Fallot (TOF). Although ICD therapies for malignant ventricular arrhythmias can be life-saving, shocks could have deleterious consequences. Substrate-based ablation therapy has become the standard of care to prevent recurrent ICD shocks in patients with ischemic cardiomyopathy. However, the efficacy and safety of this invasive therapy in the prevention of recurrent ICD shocks in patients with TOF has not been well evaluated. METHODS: Records of a total of 47 consecutive TOF patients (mean age: 43.1 ± 13.2 years, male sex: n = 34 [72.3%]) who underwent ICD implantation for secondary prevention between 2000 and 2018 were reviewed. RESULTS: Twenty (42.6%) patients underwent invasive therapy (radiofrequency catheter ablation, n = 8; surgical ablation with pulmonary valve replacement, n = 12) before ICD implantation. Twenty-seven patients (57.4%) were managed noninvasively. During follow-up (median 80.5 [interquartile range, 28.5-131.0] months), 2 (10.0%) patients in the invasive group and 10 (37.0%) patients in the noninvasive group received appropriate ICD shocks (P = 0.036). Logistic regression analysis showed that invasive therapy was associated with a decreased risk of ICD shocks by 81.1% (odds ratio, 0.189; 95% confidence interval, 0.036-0.990; P = 0.049). Furthermore, invasive therapy was associated with decreased risk of the composite outcomes of ICD shock, death, cardiac transplantation, and hospital admission (odds ratio, 0.090; 95% confidence interval, 0.025-0.365; P = 0.013) compared with noninvasive therapy. CONCLUSIONS: Invasive substrate modification therapy was associated with a lower likelihood of ICD shocks and improvement of long-term outcomes in TOF patients.

CONTEXTE: Les défibrillateurs cardioverteurs implantables (DCI) sont efficaces pour prévenir la mort cardiaque subite provoquée par une arythmie chez les patients présentant une tétralogie de Fallot (TF). Bien que le traitement des arythmies ventriculaires malignes par DCI puisse sauver des vies, les chocs administrés peuvent avoir des conséquences délétères. L'ablation du substrat est devenue le traitement de référence pour prévenir l'administration à répétition de chocs par DCI chez les patients atteints d'une cardiomyopathie ischémique. L'efficacité et l'innocuité de ce traitement invasif pour prévenir l'administration de chocs répétés chez les patients présentant une TF n'ont toutefois pas été bien évaluées. MÉTHODOLOGIE: Nous avons examiné les cas consécutifs de 47 patients présentant une TF (âge moyen : 43,1 ± 13,2 ans; hommes : n = 34 [72,3 %]) ayant reçu un DCI en prévention secondaire entre 2000 et 2018. RÉSULTATS: Au total, 20 (42,6 %) patients ont subi un traitement invasif (ablation par cathéter par radiofréquence, n = 8; ablation chirurgicale et remplacement de la valve pulmonaire, n = 12) avant l'implantation d'un DCI. Vingt-sept patients (57,4 %) ont été pris en charge de façon non invasive. Au cours de la période de suivi (durée médiane de 80,5 [intervalle interquartile : 28,5 à 131,0] mois), 2 (10,0 %) patients du groupe ayant subi une intervention invasive et 10 (37,0 %) patients du groupe ayant subi une intervention non invasive ont reçu un choc approprié par DCI (p = 0,036). Les résultats de l'analyse par régression logistique montrent que le traitement invasif est associé à une réduction du risque de choc par DCI de 81,1 % (rapport des cotes : 0,189; intervalle de confiance à 95 % : de 0,036 à 0,990; p = 0,049). En outre, le traitement invasif est associé à une réduction du risque de survenue d'un des événements du paramètre d'évaluation composé, soit un choc administré par DCI, le décès, une transplantation cardiaque ou une hospitalisation (rapport des cotes : 0,090; intervalle de confiance à 95 % : de 0,025 à 0,365; p = 0,013) par rapport au traitement non invasif. CONCLUSIONS: La modification invasive du substrat a été associée à une probabilité plus faible de choc administré par DCI et à une amélioration des résultats à long terme chez les patients présentant une TF.

Safety and Long-term Outcomes of Defibrillator Therapy in Patients With Right-Sided Implantable Cardiac Devices in Adults With Congenital Heart Disease.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) have been proven to prevent sudden cardiac death in adult congenital heart disease (ACHD) patients. Although the left side is chosen by default, implantation from the right side is often required. However, little is known about the efficacy and safety of right-sided ICDs in ACHD patients. METHODS: In this study we reviewed a total of 191 ACHD patients undergoing ICD/cardioverter resynchronisation therapy-defibrillator (CRT-D) implantation at our hospital between 2001 and 2019 (134 men and 57 women; age [mean ± standard deviation], 41.5 ± 14.8 years). RESULTS: Twenty-seven patients (14.1%) had right-sided devices. The most common causes of right-sided implantation were persistent left superior vena cava and vein occlusion (37.0%). Although procedure time (202.8 ± 60.5 minutes vs 143.8 ± 69.1 minutes, P = 0.008) was longer and the procedural success was lower (92.6% vs 99.4%, P = 0.008) for right-sided devices, no difference in R-wave and pacing threshold were noted. Among the 47 patients (24.6%) who underwent defibrillation threshold testing (DFT), no difference in DFT was observed (25.2 ± 5.3 J vs 23.8 ± 4.1 J, P = 0.460). During the median follow-up of 42.4 months, appropriate ICD therapy was observed in 5 (18.5%) and 30 (18.3%) patients for right- and left-sided ICDs/CRTDs, respectively (P = 0.978). No significant difference was seen in complications between them. CONCLUSIONS: Implantation of an ICD on the right side is technically challenging, but it is feasible as an alternative approach for ACHD patients with contraindications to left-sided device implantation.

Magnitude and Clinical Predictors of Blood Pressure Changes in Patients Undergoing Hyperbaric Oxygen Therapy: A Retrospective Study.

Hyperbaric oxygen therapy (HBOT) is widely used to treat several pathologies. The hemodynamic changes during HBOT, particularly the magnitude of arterial blood pressure (ABP) increase, are not completely understood. No clinical predictors for HBOT-induced ABP increase have been described. The purpose of this study was to quantify ABP changes in patients undergoing HBOT and to examine their predictors. This retrospective longitudinal cohort study examined 3291 elective HBOT sessions. Non-invasive ABP was recorded before and after each session. The primary outcome was to quantify the HBOT-induced ABP rise. The secondary outcome was to determine the ABP-rise predictors among demographic and clinical variables. Overall, ABP increased significantly after HBOT; this finding was more evident in the hypertensive subgroup compared to the normotensive one (+6 vs. +16.2 mmHg). Clinical predictors of significant post-HBOT ABP change were history of hypertension and pre-session baseline ABP classification. This study demonstrates an absolute HBOT-induced ABP rise. This change is clinically relevant in patients with history of hypertension. A higher baseline ABP seems a risk factor for clinically relevant ABP change. Pre-session ABP should be used clinically as an indicator for strict ABP monitoring during HBOT; future studies are recommended to explore the ABP optimization before starting an HBO treatment.

Scar Detection by Pulse-Cancellation Echocardiography: Validation by CMR in Patients With Recent STEMI.

OBJECTIVES: This study sought to assess an echocardiographic approach (scar imaging echocardiography with ultrasound multipulse scheme [eSCAR]), based on existing multipulse ultrasound scheme, as a marker of myocardial scar in humans, compared with cardiac magnetic resonance assessing late gadolinium enhancement (CMR-LGE). BACKGROUND: The detection of myocardial scar impacts patient prognosis and management in coronary artery disease and other types of cardiac disease. The clinical experience with echocardiography suggests that the reflected ultrasound signal is often significantly enhanced in infarcted myocardial segments. METHODS: Twenty patients with a recent ST-segment elevation myocardial infarction (STEMI) (cases) and 15 patients with absent CMR-LGE (negative controls) were imaged with both the eSCAR pulse-cancellation echocardiography and CMR-LGE to assess their potential association. RESULTS: Scar was detectable at CMR-LGE in 19 of 20 STEMI patients (91%), whereas all (100%) demonstrated eSCAR at echocardiography. In the 19 STEMI patients in whom CMR-LGE was detected, regional matching between eSCAR and CMR-LGE was total, although the segmental extent of detected scar was not always superimposable, particularly in the most apical segments, a region in which eSCAR demonstrated undersensitivity for the true extent of scar. CONCLUSIONS: A 2-dimensional multipulse echocardiography allows detection of myocardial scar, reliably matching the presence and site of CMR-LGE at 30 days after STEMI, or its absence in negative controls.

Prognostic value of echocardiographic calcium score in patients with a clinical indication for stress echocardiography.

OBJECTIVES: The value of the echocardiographic calcium score (eCS) was evaluated to predict cardiac events in a multicenter cohort of subjects without known coronary disease, who underwent stress echocardiography (SE) for suspected coronary artery disease (CAD). BACKGROUND: Several studies have established that aortic valve sclerosis and/or calcification and mitral calcification, as detected by echocardiography, predict cardiovascular morbidity and mortality. The use of a semiquantitative total cardiac calcium score (eCS) to assess aortic and mitral valves, papillary muscles, and the ascending aorta has never been tested in multicenter studies; the inherent subjectivity and clinical applicability of such a parameter remains a concern. METHODS: We identified 1,303 patients from 5 Italian institutions and 1 U.S. institution, who had no known CAD and who underwent clinically-indicated pharmacological or exercise SE. They were followed up for myocardial infarction (MI) and all-cause death. eCS was assessed from archived images, and its discrimination and reclassification prognostic potential was determined. RESULTS: Fifty-eight patients met the combined endpoint of all-cause death (n = 37; 2.8%) or MI (n = 21; 1.6%) during a median follow-up of 808 days. Age, diabetes mellitus, eCS >0, and ischemic SE were multivariate predictors of hard events. Kaplan-Meier curves demonstrated that patients with ischemic SE or eCS >0 had worse outcomes. When both variables were abnormal, the prognosis was worse (p < 0.001). The multivariate model demonstrated that both eCS and ischemic SE independently contributed to risk prediction more than clinical variables. Both wall motion during SE and eCS were able to significantly reclassify the risk of events, but only stress wall motion demonstrated an incremental discrimination value. CONCLUSIONS: eCS demonstrated significant prognostic value in predicting hard cardiac events in a multicenter population of patients who required noninvasive evaluation. Its value was independent from clinical assessment and wall motion during SE, although it did not show incremental value over these factors for discrimination of patients with and without events.

Cardiac calcium score on 2D echo: correlations with cardiac and coronary calcium at multi-detector computed tomography.

BACKGROUND: To test the hypothesis that a semi-quantitative echocardiographic calcium score (eCS) significantly correlates with cardiac calcium measured by coronary computed tomography angiography (CCTA) and, secondarily, severe coronary artery calcifications and stenosis. METHODS: This is a retrospective, observational study, conducted in a tertiary centre. eCS was compared with CCTA scores of non-coronary cardiac calcium (nCACS), coronary cardiac calcium (CACS) and number of diseased coronary vessels, in 141 subjects without known coronary artery disease (CAD), who underwent both echocardiography and CCTA for clinical reasons. RESULTS: Age, prevalence of hypertension and all measures of calcium (eCS, nCACS and CACS) differed significantly between the no-CAD and CAD subgroups. eCS was positively correlated with nCACS (Spearman rho = 0.64, p < 0.0001), CACS (rho = 0.46, p < 0.01) and weakly with the number of diseased coronary vessels (rho = 0.28, p < 0.05). eCS and nCACS had similar area under the curve (AUC) for the prediction of severe CACS (≥400) (0.77, 95% CI 0.68-0.86 and 0.79, 95% CI 0.72-0.88) or obstructive CAD (0.63, 95% CI 0.54-0.72 and 0.63, 95% CI 0.55-0.73). CONCLUSIONS: eCS, a calcium score easily obtainable during standard echocardiography, is moderately to strongly correlated with nCACS by CCTA. The full eCS score correlates with nCACS better than its single components. It correlates with CACS and predicts severe coronary calcification (CACS > 400), a known predictor of cardiovascular morbidity and mortality. The eCS also predicts obstructive CAD, incrementally to age and clinical variables, although for this purpose CACS remains the most accurate score.