T-wave inversion and diastolic dysfunction in patients with electrocardiographic left ventricular hypertrophy.

OBJECTIVES: The aim of this study was to investigate if T-wave inversion (TWI) in the settings of electrocardiogram (ECG)-left ventricular hypertrophy (LVH) is associated with advanced diastolic dysfunction (DD) in subjects with preserved ejection fraction (EF). BACKGROUND: Animal studies suggested that an abnormal transmural repolarization sequence from endocardium to epicardium may contribute to DD. However, little is known about abnormal repolarization sequence and DD in humans. METHODS: We studied 231 patients with ECG-diagnosed LVH and with an EF of 50% or greater (measured within 6 months of the index ECG). T-wave inversion was assessed on leads I, aVL, V(4), V(5), or V(6). Diastolic dysfunction was defined based on echocardiographic estimation of the left atrial pressure. We used multiple logistic regression to estimate the odds ratio of DD comparing patients with TWI with those without TWI. RESULTS: The average age was 65.0 ± 14.2 years, and 61% were women. The mean EF was 61.8% ± 6.6%. Patients with TWIs were more likely to have coronary artery disease (P = .013) and diabetes (P = .007). There was a 5.6-fold increased odds of DD in patients with TWI compared with those without TWI in a model adjusting for sex, age, relative wall thickness, body mass index, hypertension, coronary artery disease, diabetes, hyperlipidemia, and smoking. When comparing different echocardiographic estimates of the left atrial pressure, patients with TWI displayed higher values for septal and lateral E/e', left atrial volume index, and right ventricular/right atrial peak systolic gradient (P < .01 for each parameter). CONCLUSIONS: T-wave inversion is associated with increased odds of DD in patients with ECG-LVH with preserved systolic function. The reversal of the normal sequence of repolarization manifested on the 12-lead ECG as TWI may be a factor to DD.

Allometric model improves scaling of left atrial size in obese population: the use of body weight containing variables is challenged.

BACKGROUND: Scaling left atrial (LA) size remains a challenge. An allometric model using body weight (BW) as scaling variable was recently proposed. We sought to examine the performance of this model in an obese population. METHODS: A total of 266 consecutive overweight (110) and obese subjects (class I, II, and III obese 81, 47, and 28, respectively) were studied; 46 normal subjects with normal body mass index (BMI) served as controls. LA dimension (LAD) was scaled to BW, body surface area (BSA), BMI and height, respectively, using both isometric and allometric models. RESULTS: There were no significant differences in age, gender, or height among the five groups. The prevalence of comorbid conditions, wall thickness, E/E' and LAD measures increased significantly with increasing weight group (P < 0.01-0.001). With the isometric model, LAD corrected by BW, BSA, and BMI significantly but paradoxically decreased across the groups (P < 0.05-0.001). With the allometric model, LAD overcorrection by BM, BSA, and BMI was improved, but remained in the class III obese group. In contrast, scaling LAD to height showed significant and graded increase across the five groups in accordance with the increases of BMI, E/E' and the prevalence of comorbid conditions. CONCLUSION: All isometric models that correct LAD by BW or BW containing variables underestimate LA size in overweight and obese groups. The allometric model using height provides more consistent results and should be preferred to models using BW or BW containing variables in scaling LAD in obese population.

Laser Lead Extraction Complicated by Avulsed Tricuspid Subvalvular Apparatus with Severe Tricuspid Regurgitation.

The use of laser lead extraction (LLE) to remove pacemaker or implantable cardioverter-defibrillator leads has become increasingly prevalent. This advanced technique has been shown to be highly effective and safe. We report a rare case of severe traumatic tricuspid regurgitation after LLE that led to death.

Fatal pheochromocytoma crisis precipitated by dobutamine stress echocardiography.

The safety of dobutamine stress echocardiography (DSE) has been demonstrated in multiple studies with a major complication rate of <1%. Specifically, ventricular tachycardia during DSE has a reported incidence of 0.3%, and has been bound to be of no prognostic significance in patients without obstructive coronary artery disease. We report a unique case of fatal pheochromocytoma crisis precipitated by DSE in a patient with heretofore unknown adrenal disease. We are once again reminded that no diagnostic modality is absolutely without risk; however, minimal they might be.

Geometric determinants of functional tricuspid regurgitation: insights from 3-dimensional echocardiography.

BACKGROUND: Tricuspid regurgitation (TR) is an important predictor of morbidity and mortality in heart failure. We aimed to examine the 3D geometry of the tricuspid valve annulus (TVA) in patients with functional TR, comparing them with patients with normal tricuspid valve function and relating annular geometric changes to functional TR. METHODS AND RESULTS: TVA shape was examined by real-time 3D echocardiography in 75 patients: 35 with functional TR and 40 with normal tricuspid valve function (referent group). The 3D shape of the TVA was reconstructed from rotated 2D planes, and the annular plane was computed by least-squares fitting. Annular area and mediolateral, anteroposterior, and high (superior)-low (inferior) distances were calculated. TR was assessed by vena contracta width. The normal TVA has a bimodal pattern (high-low distance=7.23+/-1.05 mm). High points were located anteroposteriorly, and low points were located mediolaterally. With moderate or greater TR (vena contracta width 5.80+/-2.62 mm), the TVA became dilated (17.24+/-4.75 versus 9.83+/-2.18 cm2, P<0.0001, TR versus referent), more planar with decreased high-low distance (4.14+/-1.05 mm), and more circular with decreased ratio of mediolateral/anteroposterior (1.11+/-0.09 versus 1.32+/-0.09, P<0.0001, TR versus referent). CONCLUSIONS: The normal TVA has a bimodal shape with distinct high points located anteroposteriorly and low points located mediolaterally. With functional TR, the annulus becomes larger, more planar, and circular. These changes in annular shape with TR have potentially important mechanistic and therapeutic implications for tricuspid valve repair.

Echocardiographic Assessment of Right Ventricular Volume and Function.

Echocardiographic evaluation of right ventricular volume and function has become a subject of growing interest with the increasing awareness of the important role of the right ventricle in the entire circulation. However, the anatomically complex and load-dependent shaped right ventricle shape is difficult to describe by a simple geometric figure and its volume and function are, therefore, difficult to assess in a simple manner. A number of echocardiographic methods for evaluating right ventricular volume and function have emerged; to date, however, their quantification remains a clinical challenge. The major goal is to develop a reproducible method that will allow for quantitative comparisons between patients or serially within a given patient. This discussion examines the available methods with specific attention to their reliability and limitations. Visual inspection or measurement of single plane indices is limited by their lack of standardization and failure to describe the entire right ventricle. Simpson's rule requires computer calculations and assumes an elliptic symmetry present in the left, but not the right ventricle. Application of the area-length method to the subcostal outflow tract and apical four-chamber views is a particularly practical current approach. Three-dimensional echo reconstruction, which eliminates the need for geometric assumptions and individual standardized views, although only in its infancy, promises to be the most accurate method for right ventricular volume calculation and in the future should emerge as the standard for research and many clinical applications.

Left heart chamber quantification in obese patients: how does larger body size affect echocardiographic measurements?

BACKGROUND: Accurate normalization of cardiac chamber size in the obese population is a challenge. The aim of this study was to develop and assess the performance of allometric models for scaling left heart chamber sizes, including left atrial anteroposterior dimension (LADAP), left atrial volume (LAV), left ventricular end-diastolic volume (LVEDV), and left ventricular end-diastolic dimension (LVEDD), in an obese population. METHODS: To normalize left heart chamber measurements (Y: LADAP, LAV, LVEDV, and LVEDD) to body size variables (X: height, weight, body mass index, and body surface area), both isometric models (Y = aX) and optimal allometric models (Y = aX(b)) were tested. A logarithmic transformation (LnY = Lna + b × LnX) and ordinary least squares linear regression was performed to estimate the allometric scaling exponents. Pearson's correlation coefficients were obtained for measured and indexed left chamber sizes using both isometric and allometric models against body size variables. Gender-specific allometric models were also derived as sensitivity analyses. RESULTS: A total of 717 healthy obese subjects were included in the analysis. The mean body surface area and body mass index were 2.3 m(2) and 42.2 kg/m(2), respectively. Measured LADAP, LAV, LVEDD, and LVEDV were positively correlated with body size variables. Allometric scaling of LADAP, LAV, LVEDD, and LVEDV showed stronger correlation with measured chamber sizes compared with isometric scaling. The overcorrection caused by isometric scaling significantly improved after allometric models were used. The sensitivity analysis showed no significant differences in scaling exponents between men and women. CONCLUSIONS: Normalizing cardiac chamber measurements with allometric scaling methods is superior to the use of isometric methods in removing the effects of body size and minimizing overcorrection in the obese population. Using an allometric model with height provides the most accurate results.

Fatty infiltration of the aortic valve.

We report, to the best of our knowledge, the first case of fatty infiltration involving a semilunar cardiac valve. A non-obese 79-year-old man had an echogenic mass in the right coronary cusp on transesophageal echocardiography attributed to fatty infiltration. Fat in this location is extraordinary, and may arise from pluripotential interstitial myofibroblast-like cells, perhaps due to valvular injury.