Devastating fungal endocarditis involving ascending aorta in a patient with a history of aortic valve replacement: a case report.

BACKGROUND: Fungal endocarditis is a rare but serious condition associated with high mortality rates. Various predisposing factors contribute to its occurrence, such as underlying cardiac abnormalities, cardiac surgeries, prosthetic cardiac devices, and central venous catheters. Diagnosing fungal endocarditis, particularly Aspergillus, poses challenges, often complicated by negative blood cultures. CASE PRESENTATION: This report details a case of extensive ascending aorta involvement in Aspergillus endocarditis (AE) in a 24-year-old man with a history of bioprosthesis aortic valve replacement (AVR). Three months post-AVR, he presented with pericardial effusion and aortic rupture, leading to a redo biological valved conduit aortic root replacement (Bentall surgery). Despite the intervention, the tubular graft exhibited extensive Aspergillus involvement, resulting in graft disruption and significant peri-aortic infection. A second redo procedure involving aortic homograft root replacement was performed. Unfortunately, the patient succumbed two days after the surgery. CONCLUSION: A combined approach of medical and surgical therapies is recommended to manage fungal endocarditis. Despite efforts, the mortality rate associated with Aspergillus endocarditis remains unacceptably high, with no significant difference observed between combination therapy and antifungal treatment alone. Further research is essential to explore novel therapeutic strategies and improve outcomes for patients with this challenging condition.

The effect of significant weight loss after bariatric surgery on echocardiographic indices: an observational study focusing on left ventricular deformation by 2D speckle echocardiography and right ventricular size.

BACKGROUND: Obesity is a known risk factor for atherosclerosis and cardiac disease. HYPOTHESIS: This study evaluated the effect of significant weight loss following bariatric surgery on myocardial deformation indices and right ventricular size (RV). This was a prospective cohort study. Morbid obese patients scheduled for bariatric surgery from July 2017 to February 2018 at Firoozgar Hospital were included in our study and referred for transthoracic echocardiography at Rajaie Cardiovascular Medical and Research Center. RESULTS: Thirty-four patients entered the study. The absolute value of global longitudinal strain (GLS) at baseline, 3, and 6 months after surgery was 17.42 ± 2.94%, 18.24 ± 3.09%, and 19.52 ± 2.78%, respectively, with a statistically significant difference from baseline to after six months (P value < 0.001). The absolute value of global circumferential strain (GCS) at baseline, 3, and 6 months after surgery was 20.14 ± 4.22%, 23.32 ± 4.66%, and 24.53 ± 4.52%, respectively, with statistically significant changes (P value < 0.001) from baseline to three months and from baseline to six months and no significant difference from three months to six months. A significant decrease was reported in mechanical dispersion of circumferential strain (38.05 ± 23.81-23.37 ± 20.86 ms, P value = 0.006) 6 months after surgery. Right ventricular size three- and six-month post-surgery showed a significant decrease relative to baseline echocardiography. CONCLUSIONS: Bariatric surgery could enhance cardiac function, as proven by 2D speckle echocardiography. Changes in RV size may be related to weight loss and should be considered when assessing patients who have undergone bariatric surgery.

Revisiting echocardiographic features of prosthetic heart valves: the necessity of correct differentiation of mono-leaflet vs. bileaflet mechanical heart valves in a case report.

BACKGROUND: Mechanical heart valve replacement is a standard treatment for severe valvular disorders. The use of mono-leaflet valves has decreased recently. Recognizing the echocardiographic features of mono-leaflet and bileaflet valves is crucial for accurate complication diagnosis and proper management. CASE PRESENTATION: A 65-year-old female with mono-leaflet mitral and bileaflet tricuspid valves underwent an echocardiographic assessment. This simple educational case provides a unique opportunity to compare the echocardiographic features of these valves within a single patient. CONCLUSION: There is a crucial need for clinicians, particularly those in training, to differentiate between mono-leaflet and bileaflet mechanical heart valves adeptly. With mono-leaflet valves decreasing in prevalence, proficiency in recognizing the echocardiographic nuances of each type is imperative. Failure to do so may result in misdiagnoses and inappropriate management. This underscores the significance of continuous education and vigilance in echocardiographic assessments to ensure optimal patient care.

Echocardiographic estimation of left ventricular filling pressures in heart transplant recipients.

BACKGROUND: Echocardiographic estimation of left ventricular filling pressure in heart transplant (HTx) recipients is challenging. The ability of echocardiography to detect elevated left ventricular end-diastolic pressure (LVEDP) in HTx patients was assessed in this study. RESULTS: This descriptive cross-sectional study included 39 HTx recipients who were candidates for endomyocardial biopsy as a part of their routine post-transplantation surveillance. Doppler transthoracic echocardiography was done before the procedure, and left heart catheterization was done during the endomyocardial biopsy. Thirty-nine patients (15 female, 24 male), with a mean age of 39.6 years (range 13-70), were enrolled. A strong relation was observed between lateral E/e' and LVEDP (R = 0.64, P value < 0.001) and average E/e' and LVEDP (R = 0.6, P value < 0.001). The best cutoff value for LVEDP prediction was the average E/e' ≥ 6.8 with a sensitivity of 96.15% and specificity of 68.5% for the prediction of LVEDP more than or equal to 20 mmHg. Two predictive models comprising age, gender, and lateral E/e' or average E/e' were also proposed. A significant relationship was also found between LVEDP and left ventricular global longitudinal strain (R = - 0.31, P value < 0.01). CONCLUSIONS: Lateral E/e' was the best predictor of LVEDP. The cutoff of average E/e' had the best validity for the estimation of LVEDP. Despite the strong observed association, echocardiographic parameters cannot be considered a surrogate for invasive LVEDP measurements when seeking information about left ventricle filling pressure on heart transplant recipients.

Impact of Obesity and Bariatric Surgery on Metabolic Enzymes and P-Glycoprotein Activity Using the Geneva Cocktail Approach.

The inter-individual variability of CYP450s enzyme activity may be reduced by comparing the effects of bariatric surgery on CYP-mediated drug elimination in comparable patients before and after surgery. The current research will use a low-dose phenotyping cocktail to simultaneously evaluate the activities of six CYP isoforms and P-gp. The results showed that following weight reduction after surgery, the activity of all enzymes increased compared to the obese period, which was statistically significant in the case of CYP3A, CYP2B6, CYP2C9, and CYP1A2. Furthermore, the activity of P-gp after surgery decreased without reaching a statistical significance (p-value > 0.05). Obese individuals had decreased CYP3A and CYP2D6 activity compared with the control group, although only CYP3A was statistically important. In addition, there was a trend toward increased activity for CYP1A2, CYP2B6, CYP2C9, and CYP2C19 in obese patients compared to the control group, without reaching statistical insignificance (p-value ≥ 0.05). After six months (at least), all enzymes and the P-gp pump activity were significantly higher than the control group except for CYP2D6. Ultimately, a greater comprehension of phenoconversion can aid in altering the patient's treatment. Further studies are required to confirm the changes in the metabolic ratios of probes after bariatric surgery to demonstrate the findings' clinical application. As a result, the effects of inflammation-induced phenoconversion on medication metabolism may differ greatly across persons and drug CYP pathways. It is essential to apply these results to the clinic to recommend dose adjustments.

Left ventricular strain echocardiography in advanced uremic cardiomyopathy compared to dilated cardiomyopathy.

BACKGROUND: Cardiac involvement is common in end-stage renal disease patients. The presenting study aimed to evaluate the global and segmental longitudinal strain in patients with advanced uremic cardiomyopathy (AUCM) and compare it to dilated cardiomyopathy (DCM). RESULTS: The mean global longitudinal strain (GLS) was significantly lower in AUCM (P value = 0.045). Comparing segmental strain showed a lower strain in mid inferoseptal (P value = 0.048), base and mid anterolateral (P value = 0.026, 0.001 respectively), base and mid anteroseptal (P value = 0.005, 0.009 respectively), base and mid inferior (P value = 0.015, 0.034 respectively) and mid anterior (P value = 0.015) in patients with AUCM compared with DCM. In both groups, the segmental strain increased from base to apex. CONCLUSIONS: Segmental and GLSs in advanced uremic cardiomyopathy were significantly lower than those of dilated cardiomyopathy. In both groups, the segmental strain increased from base to apex.

NT-proBNP level as a substitute for myocardial perfusion scan in preoperative cardiovascular risk assessment in noncardiac surgery.

BACKGROUND: Preoperative cardiovascular risk assessment is one of the main principles before noncardiac surgeries. Cardiac stress imaging, such as myocardial perfusion scan (MPS), is a proposed cardiovascular risk evaluation method according to the latest guidelines. Yet, its efficacy, along with the cost-effectiveness of the method, has been questioned in previous studies. Our study aims to evaluate the utility of N-terminal pro-b-type natriuretic peptide (NT-proBNP) level measurement in predicting postoperative cardiovascular complications in candidates who have undergone an MPS before surgery and compare the results. METHODS: A cohort of 80 patients with a revised cardiac risk index score of one or more who were scheduled for moderate to high-risk noncardiac surgeries and met the criteria to undergo an MPS for risk assessment were included in the study. All of them underwent an MPS one week before surgery. Their preoperative NT-proBNP, troponin levels, and electrocardiograms were obtained one day before surgery and again on day three postoperative. The predictive efficacy of NT-proBNP levels and MPS were compared. RESULTS: Seventy-eight patients underwent surgery, three of which exhibited a rise in troponin level, six showed changes on electrocardiogram, and pulmonary edema was detected in one, three days after surgery. There was no mortality in our patients. The sensitivity and specificity of the MPS for predicting postoperative cardiovascular complications were 100% and 66%, respectively. MPS also had a positive predictive value of 20% and a negative predictive value of 100% in our study. A 332.5 pg/ml cut-off value for NT-proBNP level yielded a sensitivity of 100%, specificity of 79.2%, positive predictive value of 40%, and negative predictive value of 100%. CONCLUSIONS: Our study reveals the incremental specificity and positive predictive value of NT-proBNP level measurement in preoperative cardiovascular risk evaluation compared to MPS. Given the low feasibility, high costs, and disappointing predictive value of MPS, preoperative NT-proBNP level assessment can be substituted. This method can assist anesthesiologists and surgeons with precisely detecting at-risk patients resulting in taking proper measures to reduce the morbidity and mortality of the proposed patients before and during surgeries.

Cardiovascular surgical experiences of IVC tumor and thrombus: Operative strategies Based on 51 consecutive patients.

BACKGROUND: The only beneficial treatment option for the management of inferior vena cava (IVC) tumor thrombus is complete tumor removal. The aim of this study was to report our experience in surgical and clinical outcomes in patients with tumor thrombosis in IVC. METHODS: A retrospective chart review of patients who underwent surgical resection of IVC tumor at our institution over the past 10 years was performed. The patients were identified using a prospectively maintained database. RESULTS: We identified 51 patients, the mean age was 53.4 ± 16.8 years, and 25.4% were female. They were divided into three groups based on tumor thrombosis level. Twenty patients (39.2%) required sternotomy, and cardiopulmonary bypass (CPB) was used in 19 (37.2%) patients, and 2 (3.9%) cases underwent coronary artery bypass graft. The perioperative complications were severe bleeding (3 patients), pulmonary embolism (2 patients), and duodenal perforation (1 patient). Three (5.8%) in-hospital deaths occurred, and all were due to severe abdominal bleeding. After a mean follow-up time of 46.5 ± 42.0 months, 29 (56.9%) patients were alive. The mean survival time was 75.2 ± 8.4 months. In multivariate analysis, higher age (p = 0.033) and male gender (p = 0.033) proved to be independent prognostic factors. CONCLUSIONS: Tumor thrombus extending to the IVC is a rare and challenging event. Although using CPB may be safe and result in long-term survival with acceptable function, excessive bleeding during surgery may limit the use of this method.

Comparison of myocardial perfusion between the users of two antiepileptic medications: valproate vs. carbamazepine.

Objectives: The prevalence of coronary artery disease (CAD) is high in patients with epilepsy using antiepileptic drugs (AED). Epilepsy, AED, or the type and duration of AED use , may contribute to higher CAD risk.In this study, myocardial perfusion imaging (MPI) was compared between patients using carbamazepine and valproate. Method: Out of 73 patients receiving carbamazepine or valproate monotherapy for more than 2 years, visited at a tertiary referral clinic, 32 patients participated in a 2-day stress and rest phases MPI. For each phase, 15-25 mCi 99mTc-MIBI was injected, at peak exercise or by pharmacologic stimulation for the stress phase. SPECT with cardiac gating was done by a dual-head gamma camera and processed and quantified. Scans with at least one definite reversible hypo-perfusion segment were considered abnormal. Results: Seventeen patients received carbamazepine monotherapy and 15 valproates. Age and duration of AED use were similar between the groups. Two scans were abnormal (6.3%) both in valproate group (13.3%). Duration of AED use was higher in patients with abnormal scans. In patients receiving monotherapy >2 years, the frequency of abnormal MPI was similar between groups (P-value=0.12). In patients receiving monotherapy > 5 years, prevalence of abnormal MPI was higher in the valproate group (28.6% vs. 0.0%; P-value=0.042). Considering valproate subgroup, ischemic patients had higher duration of AED use, comparing with the normal patients (17.0±4.2 vs. 6.4±4.8, P-value=0.014). Conclusion: MPIs were abnormal in patients receiving valproate after 5 years compared to patients receiving carbamazepine. Long-term valproate use may increase the risk of CAD.

"Recognition of heart attack symptoms and treatment-seeking behaviors: a multi-center survey in Tehran, Iran".

BACKGROUND: In acute myocardial infarction (AMI), timely recognition of symptoms and early hospital presentation positively affect patient morbidity and mortality. Due to the high burden of ischemic heart disease in Iran, this study aimed to identify factors affecting the level of knowledge, responses at the time of AMI onset, and sources of health information among the Iranian population. METHOD: This cross-sectional study was conducted in three tertiary hospitals in Tehran, Iran. An expert-validated questionnaire was used to obtain data. A total of 400 individuals were enrolled. RESULT: Among the respondents, 285 people(71.3%) considered "chest pain or discomfort," and 251 (62.7%) regarded "pain or discomfort in the arm or shoulder" as MI symptoms. Approximately 288 (72.0%) respondents had poor knowledge of the AMI symptoms. Knowledge of symptoms was higher among those with higher levels of education, those with medical-associated jobs, and those who resided in the capital areas. Major risk factors identified by the participants were: anxiety (340)(85.0%), obesity (327)(81.8%), an unhealthy diet (325)(81.3%), and the presence of high LDL levels (258)(64.5%) and Diabetes Mellitus (164)(41.0%) were less appreciated. Calling an ambulance (286)(71.5%) was the most common treatment-seeking behavior in the case of a suspected heart attack. CONCLUSION: It is vital to educate the general population about AMI symptoms, particularly those with comorbidities at the greatest risk for an AMI episode.

A large intracardiac hydatid cyst with concomitant cervical and hepatic involvement: A case report.

Key Clinical Message: Cardiac hydatidosis is a relatively rare complication of echinococcosis. Understanding the atypical manifestations, potential associated risk factors, and epidemiology leads to optimal and timely management. Abstract: Cardiac hydatidosis is a relatively rare complication of echinococcosis, with a potentially life-threatening condition. Here, we reported a large interventricular septal hydatid cyst bulging in the left ventricle accompanied by a huge cervical lamp with recurrent hepatic cysts that underwent cardiac surgery to excise the cyst uneventfully.

Echocardiography in left atrial thrombosis.

Atrial fibrillation is one of the major predisposing factors in developing left atrial thrombosis, leading to morbidity and mortality. Echocardiography plays a paramount role in this condition's detection and subsequent treatment.

Hyepereosiniphilic syndrome and COVID-19: 2 case reports.

BACKGROUND: Nearly half of the patients with hypereosinophilic syndrome (HES) have cardiovascular involvement, a major cause of mortality. COVID-19 infection can lead to cardiac involvement, negatively impacting the clinical course and prognosis. We reported two patients with HES complicated by COVID-19, with cardiac involvement and valve replacement. CASE PRESENTATION: Our first patient was a 27-year-old woman admitted due to dyspnea and signs of heart failure. She had severe mitral stenosis and mitral regurgitation on the echocardiogram. Corticosteroid therapy improved her symptoms initially, but she deteriorated following a positive COVID-19 test. A repeated echocardiogram showed right ventricular failure, severe mitral regurgitation, and torrential tricuspid regurgitation and, she underwent mitral and tricuspid valve replacement. Our second patient was a 43-year-old man with HES resulted in severe tricuspid stenosis, which was improved with corticosteroid treatment. He underwent tricuspid valve replacement due to severe valvular regurgitation. He was admitted again following tricuspid prosthetic mechanical valve thrombosis. Initial workups revealed lung involvement in favor of COVID-19 infection, and his PCR test was positive. CONCLUSION: COVID-19 infection can change the clinical course of HES. It may result in a heart failure exacerbation due to myocardial injury and an increased risk of thrombosis in prosthetic valves or native vessels due to hypercoagulability.

Extensive right-sided endocarditis in double-chamber right ventricle presented with leukocytoclastic vasculitis.

Congenital heart disease is a risk factor for infective endocarditis (IE). Ventricular septal defects and ventricular outflow tract obstructions are this population's most common causes of endocarditis. We present a patient diagnosed with leukocytoclastic vasculitis, renal, and pulmonary involvement with right-sided IE as an etiology for vasculitis.

Successful Pregnancy after a Heart Transplant in Iran: A Case Report.

Pregnancy after a heart transplant is a concern for many female recipients, and it remains a medical challenge that raises many questions. A 24-year-old woman, gravida 3, para 0, contacted us for obstetric care in the first trimester of gestation, about 3 years after an orthotopic cardiac transplant. She was a known case of dextrocardia with congenitally corrected transposition of the great arteries. The transplant had been performed for severe retractable heart failure, manifesting during her previous lost pregnancy. The course of the current gestation was uneventful. The patient's cardiovascular function was good throughout the pregnancy. She was admitted to the hospital for dyspnea at 35 weeks and 4 days of gestational age. A cardiovascular consult and echocardiography were performed. The results were within the normal range, and labor pains explained the patient's dyspnea. Because of labor pain, a repeat Cesarean section was performed at 35 weeks and 4 days of gestational age. A male baby weighing 2700 g, with an Apgar score of 7/9, was delivered. The patient was discharged after delivery with enoxaparin (40 mg), prednisolone (5 mg), levothyroxine, and mycophenolate mofetil (500 mg) without any complications. Follow-up was carried out at 1 month, and no abnormality was found. Here, we report a case of a successful pregnancy in a young woman after a heart transplant.

Re-emphasis on the role of echocardiography in diagnosis of aortic root surgery complications.

BACKGROUND: Aortic pseudoaneurysm is an infrequent complication of ascending aorta surgery. CASES: This is a report of two cases that underwent the Bentall procedure that presented with large pseudoaneurysms. CONCLUSION: Use of multimodality imaging after Bentall surgery has been advocated for the detection of surgical complications. Although 3D CT angiography has the highest diagnostic accuracy, familiarity with transthoracic echocardiographic finding in these patients will lead to earlier diagnosis.

Right ventricular diastolic function predicts clinical atrial fibrillation after coronary artery bypass graft.

Background: Patients with moderate-severe left ventricular systolic dysfunction undergoing coronary artery bypass graft (CABG) surgery are at high risk of mortality and morbidity. Our aim is to evaluate the right ventricular (RV) diastolic function in these patients, and monitor its effects on postoperation outcomes. Materials and Methods: In a cohort study, patients with moderate-severe left ventricular systolic dysfunction (ejection fraction ≤35%) who were candidate for CABG were included. Baseline transthoracic echocardiography (TTE) was performed, and RV diastolic function measures were obtained. After CABG, the length of intubation, inotrope dependency, hospital stay in intensive care unit and ward, in-hospital and after discharge mortality, postoperative atrial fibrillation (POAF) were evaluated in all patients. Results: Sixty-seven patients were prospectively included in the study. The mean ± standard deviation age of our patients was 61.4 ± 9.3. There was no difference between grades of RV diastolic function and postoperative outcomes. However, we found significant difference between grades of RV diastolic function and onset of in hospital, and total POAF (P-value = 0.017). Multivariate analysis demonstrated that preoperative tricuspidEt/E't (ratio of peak early-diastolic flow rate across the tricuspid valve orifice to peak early-diastolic velocity at the lateral tricuspid annulus), left atrial volume and "high risk" Euroscore II were independent predictors for POAF during hospitalization and total POAF in patients with moderate to severely impaired left ventricular systolic function (P-values were 0.04, 0.003 and 0.001, respectively). Conclusion: We believe that patients with increased tricuspid Et/E't are high risk for POAF; therefore, any risk score for POAF should include a comprehensive TTE including evaluation of RV diastolic function before surgery.

Preconception consultation using treadmill exercise stress echocardiography for pregnant women with the left-sided heart valve stenosis: A preliminary report.

OBJECTIVE: Pregnancy can increase gradients across the heart valves and consequently deteriorates maternal and fetoneonatal conditions. Hence, pregnancy during heart valve diseases can be challenging and we need to risk stratify patients before conception. We tried to assess the role of preconception consultation using treadmill stress echocardiography (TSE) testing for identifying pregnancy outcomes in women with mitral valve stenosis (MS) or aortic valve stenosis (AS). METHODS: Pregnant patients with a diagnosis of MS or AS were evaluated from January 2015 to December 2018. First group included patients undergoing the TSE testing and they were permitted to get pregnant if they met pre-defined criteria. Second group comprised women who did not undergo TSE testing. Maternal and fetoneonatal outcomes were also recorded. RESULTS: A total of 29 and 18 patients with MS and AS, respectively, were recruited. Among MS patients, individuals without TSE had more functional deterioration (11.1% vs. 35%) and more fetoneonatal events (FNE) (22.2% vs. 55%) compared with those undergoing TSE. The rates of maternal events and mitral valvuloplasty during pregnancy were significantly higher in patients without TSE compared with those undergoing TSE (p=0.015 and p=0.042, respectively). Among AS patients, maternal and FNE were higher in patients without TSE compared with those undergoing TSE, but those were comparable. CONCLUSION: Pregnant patients with the left-sided valvular stenosis who received preconception TSE testing had better outcomes compared with those who did not undergo preconception consultation. This underscores the utility of stress echocardiography in the risk stratification of pregnancies.

Evaluation of phenoconversion phenomenon in obese patients: the effects of bariatric surgery on the CYP450 activity "a protocol for a case-control pharmacokinetic study".

Personalized therapy suggests the appropriate drug at the right dose for the first time through genotype-based individualized therapy, instead of prescribing medicines by the traditional one-size-fits-all manner, thereby claiming that it will make medicines safer and more effective. Accordingly, polymorphisms of drug metabolizing enzymes (DMEs), which induce inter-individual variability in the pharmacokinetics of a drug, have attracted great interest in the context of personalized medicine. Obesity is one of the most common chronic diseases in the world, including Iran, and the prevalence is increasing according to predictions. The remarkable role of P450 cytochromes has been verified in the metabolism of numerous drugs, toxins, carcinogen compounds, and the synthesis of some intrinsic compounds, such as steroid hormones. Thus, evaluating the activity of these enzymes is of great importance because any functionality variation can lead to failure in the treatment or unwanted side effects of some drugs. Therefore, any change in the activity of these enzymes in obese patients can also be problematic in the treatment process of these patients in comparison to normal weighted ones. Since only a few human studies have examined the role of inflammation in altering the function of these enzymes, it seems to be necessary to investigate the effect of obesity on the expression and activity of these enzymes; in which the role of inflammatory processes has been proven. Most importantly, it is worth evaluating changes in the activity levels of cytochrome P450 (CYP450) and the inflammatory cytokines after a course of post-surgical treatment and weight loss. To evaluate the activity of CYPs, a multi-drug cocktail is prescribed to obese patients before and after obesity surgery, as well as to healthy volunteers, to provide simultaneous evaluation of different isoforms. A complete demographic data, medical examinations, laboratory tests, and the CYPs genotype of all participants can be extremely important during this investigation.

Additive value of positron emission tomography/computed tomography scan for detection of aortic tube graft infection: a case report.

BACKGROUND: Diagnosis of aortic graft infection is challenging, and delayed diagnosis is associated with poor prognosis. Positron emission tomography/computed tomography (PET/CT) has improved diagnostic accuracy. CASE SUMMARY: A patient with a history of congenital heart disease was admitted due to fever. He had a history of four cardiac surgeries, including the Bentall procedure for endocarditis. Blood cultures were negative. A semi-mobile mass was detected in the distal portion of the aortic tube graft in echocardiography. PET/CT scan was used to confirm tube graft infection and to support proceeding to cardiac surgery. DISCUSSION: Using multimodality imaging, including PET/CT scan in combination with echocardiography, can improve diagnostic accuracy for the detection of aortic tube graft infection, infection of prosthetic valves, or intra-cardiac devices, especially in high-risk surgical cases.