Left ventricular end-diastolic pressure is a predictor of mortality in cardiac surgery independently of left ventricular ejection fraction

Maternal diet-induced obesity programs cardiovascular dysfunction in adult male mouse offspring independent of current body weight

Obese pregnancies are not only associated with adverse consequences for the mother but also the long-term health of her child. Human studies have shown that individuals from obese mothers are at increased risk of premature death from cardiovascular disease (CVD), but are unable to define causality. This study aimed to determine causality using a mouse model of maternal diet-induced obesity. Obesity was induced in female C57BL/6 mice by feeding a diet rich in simple sugars and saturated fat 6 weeks prior to pregnancy and throughout pregnancy and lactation. Control females were fed laboratory chow. Male offspring from both groups were weaned onto chow and studied at 3, 5, 8, and 12 weeks of age for gross cardiac morphometry using stereology, cardiomyocyte cell area by histology, and cardiac fetal gene expression using qRT-PCR. Cardiac function was assessed by isolated Langendorff technology at 12 weeks of age and hearts were analyzed at the protein level for the expression of the β1 adrenergic receptor, muscarinic type-2 acetylcholine receptor, and proteins involved in cardiac contraction. Offspring from obese mothers develop pathologic cardiac hypertrophy associated with re-expression of cardiac fetal genes. By young adulthood these offspring developed severe systolic and diastolic dysfunction and cardiac sympathetic dominance. Importantly, cardiac dysfunction occurred in the absence of any change in corresponding body weight and despite the offspring eating a healthy low-fat diet. These findings provide a causal link to explain human observations relating maternal obesity with premature death from CVD in her offspring.

The novel regulations of MEF2A, CAMKK2, CALM3, and TNNI3 in ventricular hypertrophy induced by arsenic exposure in rats

Arsenic is a ubiquitous toxic compound that exists naturally in many sources such as soil, groundwater, and food; in which vast majority forms are arsenite (As(3+)) or arsenate (As(5+)). The mechanism of arsenic detoxification in humans still remains obscured. Epidemiologic studies documented that arsenic pollution caused black foot disease, cardiovascular diseases (hypertension, hypotension, cardiomyopathy), bladder cancer and skin cancer in many countries in which Taiwan is considered as high arsenic exposure country for long time ago. However, the effects of arsenic to cardiac functions still lacked of investigation while some studies mainly focus on inflammatory and cancer mechanisms. In the present study, we found cardiac hypertrophy signaling may be the most significant pathway for up regulated genes in arsenic exposed patients via bioinformatics approach. To verify our bioinformatics prediction, arsenic was fed orally to rats at different concentration based on previous studies in Taiwan. Using hemodynamic method as the main tool to measure the changes in blood pressure, left ventricular pressure and left ventricular contractility index, the findings suggest that highly exposure to arsenic lead to hypertension; elevated left ventricular diastolic pressure and alteration in cardiac contractility which are supposed to be the interaction between arsenic and cardiac nerves activity via the changing in calcium homeostasis. Collectively, based on our real-time PCR and western blot data strongly suggest that calcium homeostasis may also go through MEF2A, TNNI3, CAMKK2, CALM3 and cardiac hypertrophy relative signaling pathway.

Practical diastology

Left ventricular (LV) diastolic dysfunction is being recognized as an important part in the pre-operative evaluation. Pre-operative LV diastolic dysfunction has been associated with increased risk of post-operative complications. Furthermore guidelines have been published on the assessment of LV diastolic function. However LV diastolic function is significantly influenced by loading conditions which are typically altered during cardiac and non-cardiac surgery. In addition, waveform analysis from the pulmonary artery catheter tend to correlate with diastolic function and loading conditions. The advantage of hemodynamic monitoring being that they are continuously displayed as opposed to intermittent diastolic parameters. Finally if the importance of diastolic function assessment is to estimate filling pressure, the presence of B lines with the use of lung ultrasound is a simpler method in detecting pulmonary edema. Another indirect evidence of either LV systolic or diastolic dysfunction is an abnormal near-infrared spectroscopy value. Finally it might be more important to evaluate right ventricular (RV) diastolic dysfunction as RV dysfunction is significantly associated with pulmonary hypertension and consequently mortality. Such assessment of RV diastolic dysfunction can be obtained continuously with the use of RV pressure waveform monitoring.

Left ventricular end-diastolic pressure as an independent predictor of outcome during balloon aortic valvuloplasty

OBJECTIVES

In this study, we examined the predictive value of the left ventricular end-diastolic pressure (LVEDP) in patients undergoing balloon aortic valvuloplasty (BAV).

BACKGROUND

The LVEDP is a useful indicator of hemodynamic status in patients with severe aortic stenosis. In BAV, decompensated heart failure is associated with worse outcomes.

METHODS

We identified all consecutive patients with severe symptomatic aortic stenosis who underwent retrograde BAV at the Massachusetts General Hospital from 2004 to 2008. Patients were stratified and compared according to their baseline LVEDP into ≤15 mm Hg, 16-20 mm Hg, 21-25 mm Hg, and ≥26 mm Hg. Procedural and in-hospital outcomes and adverse events were compared. Multivariate logistic regression was used for the adjusted analysis.

RESULTS

A total of 111 patients with a mean age of 83±11 years underwent BAV. Of these, the LVEDP was ≤15 mm Hg in 29 (26%), 16-20 mm Hg in 41 (37%), 21-25 mm Hg in 16 (14%), and ≥26 mm Hg in 25 (23%) patients. Baseline characteristics were similar among the four groups. Noticeably, patients with high LVEDP levels had significantly higher rates of the combined endpoint of in-hospital death, myocardial infarction (MI), cardiopulmonary arrest, and tamponade was P = 0.02. Periprocedural MI was more common among those with higher LVEDP (16% vs. 2.3%; P = 0.04). Multivariate analysis revealed LVEDP (OR 1.08, for each mm Hg increase in pressure, 95 % CI 1.02-1.14), small LV chamber size, and New York Heart Association class as independent predictors of adverse outcomes.

CONCLUSIONS

The LVEDP is an important independent predictor of poor in-hospital outcome during BAV. In these patients, the immediate hemodynamic status may be more important than the baseline left ventricular systolic function. Hemodynamic optimization before or during BAV should be considered and may be beneficial.

Developmental programming of cardiovascular disease by prenatal hypoxia

It is now recognized that the quality of the fetal environment during early development is important in programming cardiovascular health and disease in later life. Fetal hypoxia is one of the most common consequences of complicated pregnancies worldwide. However, in contrast to the extensive research effort on pregnancy affected by maternal nutrition or maternal stress, the contribution of pregnancy affected by fetal chronic hypoxia to developmental programming is only recently becoming delineated and established. This review discusses the increasing body of evidence supporting the programming of cardiac susceptibility to ischaemia and reperfusion (I/R) injury, of endothelial dysfunction in peripheral resistance circulations, and of indices of the metabolic syndrome in adult offspring of hypoxic pregnancy. An additional focus of the review is the identification of plausible mechanisms and the implementation of maternal and early life interventions to protect against adverse programming.

Evaluation of antioxidant and immunity function of tetramethylpyrazine phosphate tablets in vivo

The aim of the study was to determine the effect of tetramethylpyrazine phosphate tablets (TPT), a Chinese medicine used for cardiovascular disease, on immunity activity and oxidative injury in rats. Heart failure (HF) was induced by isoproterenol (ISO). After the animal model was established, the rats were administered the TPT by gavage (once a day). The results indicated that TPT improved left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), ±dP/dt, heart weight/body weight. TPT could decrease the levels of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6). Furthermore, it also could raise the activities of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), but reduce malonyldialdehyde (MDA) level. The results indicated that TPT improved cardiac function and myocardial fibrosis from myocardial injury, and this cardioprotection might be attributed to a reduction of oxidative stress and regulation of inflammation mediators.

[Intraoperative ejection fraction: estimation with Simpson's rule vs tissue Doppler imaging]

BACKGROUND

Transesophageal echocardiography is appropriate for intraoperative monitoring of hemodynamics. The parameter often estimated is ejection fraction (EF) by means of Simpson's rule. With the advent of tissue Doppler imaging and measurement of the systolic (S) wave, corresponding to the rate of myocardial perfusion during the systole, it is possible to estimate the EF more easily and rapidly during surgery.

OBJECTIVE

To compare EF estimates obtained by Simpson's rule to those based on intraoperative tissue Doppler measurements of S-wave velocity (S').

MATERIAL AND METHODS

Patients with chronic cardiovascular disease undergoing scheduled cardiac and noncardiac surgery were studied. Patients in nonsinus rhythm and with mitral valve disease were excluded. To apply Simpson's rule for calculating the EF, we measured end-diastolic volume in 4- and 2-chamber views. The group was divided into patients with normal (> or = 50%) and diminished (< or = 49%) ejection fraction. Tissue Doppler imaging of the mitral annulus was then used to measure S'. Ejection fraction was calculated according to the formula EF = 5.5 x S' + 8.

RESULTS

Ninety-two patients were studied; in 51 (55%) the EF was normal and in 41 (45%) it was reduced. In patients whose EF was < or = 49% according to Simpson's rule, the correlation between that measurement and EF based on tissue Doppler estimate of S' was good. The correlation was lower, however, in the group with normal EF (r=0.61; P>0.5).

CONCLUSIONS

EF is easy to estimate with tissue Doppler imaging and the procedure is reproducible. This approach is probably more useful in patients with left ventricular dysfunction.

Perioperative assessment of diastolic dysfunction

Assessment of diastolic function should be a component of a comprehensive perioperative transesophageal echocardiographic examination. Abnormal diastolic function exists in >50% of patients presenting for cardiac and high-risk noncardiac surgery, and has been shown to be an independent predictor of adverse postoperative outcome. Normalcy of systolic function in 50% of patients with congestive heart failure implicates diastolic dysfunction as the probable etiology. Comprehensive evaluation of diastolic function requires the use of various, load-dependent Doppler techniques This is further complicated by the additional effects of dehydration and anesthetic drugs on myocardial relaxation and compliance as assessed by these Doppler measures. The availability of more sophisticated Doppler techniques, e.g., Doppler tissue imaging and flow propagation velocity, makes it possible to interrogate left ventricular diastolic function with greater precision, analyze specific stages of diastole, and to differentiate abnormalities of relaxation from compliance. Additionally, various Doppler-derived ratios can be used to estimate left ventricular filling pressures. The varying hemodynamic environment of the operating room mandates modification of the diagnostic algorithms used for ambulatory cardiac patients when left ventricular diastolic function is evaluated with transesophageal echocardiography in anesthetized surgical patients.

Is Peri-Operative Isolated Systolic Hypertension (ISH) a Cardiac Risk Factor?

We are presenting a review of Isolated Systolic Hypertension (ISH) as a cardiovascular risk factor with emphasis on the perioperative period.

Isolated systolic hypertension is associated with aging and is the most frequent subtype (65%) among patients with uncontrolled hypertension. ISH is strongly associated with increased risks of cardiac and cerebrovascular events exceeding those in comparably aged individuals with diastolic hypertension. Patients with ISH show an increase in left ventricular (LV) mass and an increase in the prevalence of left ventricular hypertrophy (LVH). These LV changes increase cardiovascular events and frequently lead to diastolic dysfunction (DD). Treatment to reduce elevated systolic blood pressure has been shown to reduce the risk of cardiovascular events.

In the perioperative setting, essential hypertension has not been found to be a significant risk factor for cardiac complications. Most of the studies were based on the definition of essential hypertension and underpowered in sample size. The significance of perioperative ISH, however, is not well studied, partly due to its recognition only fairly recently as a cardiovascular risk factor in the non-surgical setting, and partly due to the evolving definition of ISH.

Perioperative cardiac complications remain a significant problem to the healthcare system and to the patient. Although the incidence of perioperative cardiac complications is prominent in high-risk patients as defined by the Revised Cardiac Risk Index (RCRI), the bulk of the cardiac complications actually occur in low-risk group. Currently, little understanding exists on the occurrence of perioperative cardiac complications in low- risk patients. A factor such as ISH, with its known pathophysiological changes, is a potential perioperative risk factor.

We believe ISH is an under-recognized perioperative risk factor and deserves further studying. Our research group has recently been funded by the Heart Stroke Foundation (HSF) to examine ISH as a perioperative risk factor (PROMISE Study).

Noninvasive assessment of left ventricular end-diastolic pressure with tissue Doppler imaging in patients with mitral regurgitation

BACKGROUND

The ratio of early transmitral flow velocity to mitral annulus early diastolic velocity (E/Ea) is a widely used noninvasive tool to estimate left ventricular end diastolic pressure (LVEDP). The aim of this study was to explore whether E/Ea ratio was a reliable index for the estimation of LVEDP in patients with mitral regurgitation (MR).

METHODS

Sixteen patients with nonischemic MR (primary MR group; 6 male, 58 ± 12 years) 51 patients with ischemic MR (secondary MR group; 29 male, 63 ± 9 years) and 29 patients without MR (control group; 19 male, 53 ± 10 years) were consecutively included. The peak transmitral flow and mitral annular velocities during early diastole were measured. LVEDP was determined invasively by left heart catheterization.

RESULTS

Primary and secondary MR groups had significantly higher E/Ea ratios and LVEDP than control group. LVEDP significantly correlated with E/Ea ratio in patients with primary MR, but not in patients with secondary MR. Multiple regression analysis revealed that E/Ea ratio was an independent predictor of LVEDP in patients with primary MR. Ten patients with primary MR had LVEDP ≥15 mmHg. ROC analysis demonstrated cutoff values for E/Ea ratios as >10.5 for lateral mitral annulus (sensitivity: 80%, specificity: 66%, PPV: 80%, NPV: 66%) and as >14 for medial mitral annulus (sensitivity: 90%, specificity: 83%, PPV: 90%, NPV: 83%) to predict primary MR patients with LVEDP ≥15 mmHg.

CONCLUSION

E/Ea ratio is still reliable in estimation of LVEDP in primary MR patients while it is not predictive for LVEDP in secondary MR patients.

Focused Transthoracic Echocardiography in the Perioperative Period

Ultrasound applications in perioperative medicine have expanded enormously over the past decade. Transoesophageal echocardiography has been performed by anaesthetists during cardiac surgery for over 20 years. With the increasing availability of portable ultrasound systems, the use of ultrasound to assist in vascular cannulation and regional anaesthesia has been well described. Portable ultrasound systems come with a range of probes for different applications, including transthoracic echocardiography. While transthoracic echocardiography has traditionally been the domain of cardiologists, its use has been increasing in critical care, the emergency room and, recently, by anaesthetists in the perioperative period. Unlike formal cardiology-based transthoracic echocardiography, focused, goal-directed transthoracic echocardiography is often more appropriate in the perioperative period to address a particular question and can be performed in just a few minutes. Transthoracic echocardiography allows rapid, noninvasive, point-of-care assessment of ventricular function, valvular integrity, volume status and fluid responsiveness. It can help distinguish undifferentiated systolic murmurs preoperatively, give valuable information on the aetiology of unexplained hypotension and cardiovascular collapse and assess response to therapeutic interventions such as vasoactive drugs and volume resuscitation. Focused transthoracic echocardiography should include qualitative assessment of left and right ventricular function, an estimate of aortic valve gradient, right ventricular systolic pressure and intravascular volume status as minimum requirements. Transthoracic echocardiography is a valuable tool in the perioperative period and ideally the equipment and expertise should be available in all operating rooms.

Intraoperative Hemodynamic Instability During and After Separation From Cardiopulmonary Bypass

Every year, more than 1 million patients worldwide undergo cardiac surgery. Because of the aging of the population, cardiac surgery will increasingly be offered to patients at a higher risk of complications. The consequence is a reduced physiological reserve and hence an increased risk of mortality. These issues will have a significant impact on future health care costs because the population undergoing cardiac surgery will be older and more likely to develop postoperative complications. One of the most dreaded complications in cardiac surgery is difficult separation from cardiopulmonary bypass (CPB). When separation from CPB is associated with right-ventricular failure, the mortality rate will range from 44% to 86%. Therefore, the diagnosis and the preoperative prediction of difficult separation from CPB will be crucial to improve the selection and care of patients and to prevent complications for this high-risk patient population.

Prognostic value of tissue Doppler-Derived E/e' on early morbid events after cardiac surgery

BACKGROUND

The tissue Doppler-derived surrogate for left ventricular diastolic pressure, E/e', has been used to prognosticate outcome in a variety of cardiovascular conditions. In this study, we determined the relationship of intraoperative E/e' to the use of inotropic support, duration of mechanical ventilation (MV), length of intensive care unit stay (ICU-LOS), and total hospital stay (H-LOS) in patients requiring cardiac surgery. The records of 245 consecutive patients were retrospectively reviewed to obtain 205 patients who had intraoperative transesophageal echocardiography examinations prior to coronary artery bypass grafting and/or valvular surgery. Cox proportional hazards and logistic regression models were used to analyze the relation between intraoperative E/e' or LVEF and early postoperative morbidity (H-LOS, ICU-LOS, and MV) and the probability that a patient would require inotropic support. With adjustments for other predictors (female gender, hypertension, diabetes, history of myocardial infarction, emergency surgery, renal failure, procedure type, and length of aortic cross-clamp time), an elevated E/e' ratio (>or=8) was significantly associated with an increased ICU-LOS (49 versus 41 median h, P = 0.037) and need for inotropic support (P = 0.002) while baseline LVEF was associated with inotropic support alone (P < 0.0001). These data suggest that the tissue Doppler-derived index of left ventricular diastolic filling pressure may be a useful indicator for predicting early morbid events after cardiac surgery, and may even provide additional information from that of baseline LVEF. Further, patients with elevated preoperative E/e' may need more careful peri- and postoperative management than those patients with E/e' <8.

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

INTRODUCTION

Left ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis.

METHODS

Perioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality >or=9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp).

RESULTS

Doppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001).

CONCLUSIONS

This study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp <or= 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.

Diastolic dysfunction, cardiovascular aging, and the anesthesiologist

As the number of persons aged 65 years and older continues to increase, the anesthesiologist will more frequently encounter this demographic. Cardiovascular changes that occur in this patient population present difficult anesthetic challenges and place these patients at high risk of perioperative morbidity and mortality. The anesthesiologist should be knowledgeable about these age-related cardiovascular changes, the pathophysiology underlying them, and the appropriate perioperative management. Whether presenting for cardiac or general surgery, the anesthesiologist must identify patients with altered physiology as a result of aging or diastolic dysfunction and be prepared to modify the care plan accordingly. With a directed preoperative assessment that focuses on certain aspects of the cardiovascular system, and the assistance of powerful echocardiographic tools such as tissue Doppler, this can be achieved.

Predictors of inotrope use in patients undergoing concomitant coronary artery bypass graft (CABG) and aortic valve replacement (AVR) surgeries at separation from cardiopulmonary bypass (CPB)

BACKGROUND

Left ventricular dysfunction is common after coronary artery bypass graft and valve replacement surgeries and is often treated with inotropic drugs to maintain adequate hemodynamic status. In this study, we aimed to identify the demographic, clinical, laboratory, echocardiographic and hemodynamic factors that are associated with use of inotropic drugs in patients undergoing concomitant coronary artery bypass graft and aortic valve replacement surgery.

METHODS

The study included 97 patients who had undergone concomitant coronary artery bypass graft and aortic valve replacement at Regions Hospital, University of Minnesota Medical School from January 2006 to December 2008. All data were collected retrospectively after reviewing electronic medical records. Inotropic support was defined as the use of dopamine [greater than or equal to] 5 ug/kg/min; any dose of epinephrine, norepinephrine, dobutamine, and milrinone at the separation from cardiopulmonary bypass.

RESULTS

Inotropic support was used in a total of 50 patients (52%) at the separation from cardiopulmonary bypass. Average age of the patients requiring inotropic support was 72.2 +/- 8.8 years. The study identified four significant, independent predictors of inotrope use: (1) Cardiac index [less than or equal to] 2.5 L/min/m2, (2) LVEDP [greater than or equal to] 20 mm Hg, (3) LVEF [less than or equal to] 40%, and (4) CKD stage 3 to 5.

CONCLUSION

We identified four independent risk factors for postoperative use of inotropic support in patients undergoing concomitant coronary artery bypass graft and arotic valve replacement surgery at the separation from cardiopulmonary bypass. The study results will be helpful to prospectively identify patients who will likely to require inotropic support at the separation from cardiopulmonary bypass.

[Echocardiography-derived Tei index during surgery, a predictor of postoperative cardiovascular complications]

BACKGROUND AND OBJECTIVE

The Tei index is a Doppler echocardiographic parameter that reflects both systolic and diastolic myocardial function. Our aim was to monitor the Tei index by transesophageal echocardiography during noncardiac surgery to explore the correlation between this parameter and the incidence of postoperative cardiovascular complications.

MATERIAL AND METHODS

Patients at risk of cardiovascular complications were enrolled. The Tei index was derived from the pattern of pulsed Doppler transmitral filling and aortic outflow, by dividing the sum of isovolumetric contraction and relaxation intervals by ejection time in milliseconds.

RESULTS

Seventy-three patients (58% men) were enrolled. The mean (SD) age was 68 (12) years. Two groups were identified based on myocardial function. A Tei index over 0.35 defined group 2 (n = 25) and correlated with a larger number of postoperative cardiovascular events. In patients with a normal Tei index less than 0.35 (group 1, n = 48), the incidence of cardiovascular complications was lower. Hypotension occurred in 60% of patients in group 2 and 21% of those in group 1, hypertension in 24% of group 2 and 4.1% of group 1, and pulmonary edema in 8% of group 2 and 2.1% of group 1 (P < .05 for all comparisons).

CONCLUSIONS

This pilot study found that patients with a high Tei index were more likely to develop postoperative cardiovascular complications. This index may provide a useful indicator to take into consideration in planning hemodynamic management when patients have a history of cardiovascular disease.

Impact of Perioperative Transesophageal Echocardiography in Aortic Valve Replacement

Intraoperative transesophageal echocardiography (TEE) is currently being used routinely during aortic valve replacement (AVR). TEE provides information that can lead to modifications of anesthetic and surgical care that leads to improved outcome. Numerous studies have shown that modifications in therapy occur from 10% to more than 40% of cases. The impact of TEE can be divided among modifications of therapy before, during, and after cardiopulmonary bypass. Before cardiopulmonary bypass, TEE can provide prognostic information, optimize hemodynamics, and diagnose conditions that were not appreciated before surgery, including patient—prosthesis mismatch. TEE can guide and modify the placement of various bypass cannulae. After bypass, TEE verifies the surgical result, rules out left and right ventricular outflow tract obstruction, and assures stable hemodynamics. Although current guidelines state that aortic valve surgery is a class IIa indication for TEE use, the authors' experience suggests that TEE should be routinely used in AVR.

Implantable cardioverter-defibrillators in tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverter-defibrillator (ICD) recipients, yet little is known about the value of ICDs in this patient population.

METHODS AND RESULTS

We conducted a multicenter cohort study in high-risk patients with Tetralogy of Fallot to determine actuarial rates of ICD discharges, identify risk factors, and characterize ICD-related complications. A total of 121 patients (median age 33.3 years; 59.5% male) were enrolled from 11 sites and followed up for a median of 3.7 years. ICDs were implanted for primary prevention in 68 patients (56.2%) and for secondary prevention in 53 (43.8%), defined by clinical sustained ventricular tachyarrhythmia or resuscitated sudden death. Overall, 37 patients (30.6%) received at least 1 appropriate and effective ICD discharge, with a median ventricular tachyarrhythmia rate of 213 bpm. Annual actuarial rates of appropriate ICD shocks were 7.7% and 9.8% in primary and secondary prevention, respectively (P=0.11). A higher left ventricular end-diastolic pressure (hazard ratio 1.3 per mm Hg, P=0.004) and nonsustained ventricular tachycardia (hazard ratio 3.7, P=0.023) independently predicted appropriate ICD shocks in primary prevention. Inappropriate shocks occurred in 5.8% of patients yearly. Additionally, 36 patients (29.8%) experienced complications, of which 6 (5.0%) were acute, 25 (20.7%) were late lead-related, and 7 (5.8%) were late generator-related complications. Nine patients died during follow-up, which corresponds to an actuarial annual mortality rate of 2.2%, which did not differ between the primary and secondary prevention groups.

CONCLUSIONS

Patients with tetralogy of Fallot and ICDs for primary and secondary prevention experience high rates of appropriate and effective shocks; however, inappropriate shocks and late lead-related complications are common.