Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Acute failure of catheter ablation for ventricular tachycardia due to structural heart disease: Causes and significance

10.1161/JAHA.113.000072Journal of the American Heart Association23e00007

Effect of Sleep Apnea and Continuous Positive Airway Pressure on Cardiac Structure and Recurrence of Atrial Fibrillation

Cardiovascular Aspects of Radiolog

Myocardial Extracellular Volume Expansion And The Risk Of Recurrent Atrial Fibrillation After Pulmonary Vein Isolation

Objectives This study tested whether myocardial extracellular volume (ECV) is increased in patients with hypertension and atrial fibrillation (AF) undergoing pulmonary vein isolation and whether there is an association between ECV and post-procedural recurrence of AF. Background Hypertension is associated with myocardial fibrosis, an increase in ECV, and AF. Data linking these findings are limited. T1 measurements pre-contrast and post-contrast in a cardiac magnetic resonance (CMR) study provide a method for quantification of ECV. Methods Consecutive patients with hypertension and recurrent AF referred for pulmonary vein isolation underwent a contrast CMR study with measurement of ECV and were followed up prospectively for a median of 18 months. The endpoint of interest was late recurrence of AF. Results Patients had elevated left ventricular (LV) volumes, LV mass, left atrial volumes, and increased ECV (patients with AF, 0.34 ± 0.03; healthy control patients, 0.29 ± 0.03; p < 0.001). There were positive associations between ECV and left atrial volume (r = 0.46, p < 0.01) and LV mass and a negative association between ECV and diastolic function (early mitral annular relaxation [E′], r = -0.55, p < 0.001). In the best overall multivariable model, ECV was the strongest predictor of the primary outcome of recurrent AF (hazard ratio: 1.29; 95% confidence interval: 1.15 to 1.44; p < 0.0001) and the secondary composite outcome of recurrent AF, heart failure admission, and death (hazard ratio: 1.35; 95% confidence interval: 1.21 to 1.51; p < 0.0001). Each 10% increase in ECV was associated with a 29% increased risk of recurrent AF. Conclusions In patients with AF and hypertension, expansion of ECV is associated with diastolic function and left atrial remodeling and is a strong independent predictor of recurrent AF post-pulmonary vein isolation. © 2014 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION PUBLISHED BY ELSEVIER INC.71111Levy, D., Larson, M.G., Vasan, R.S., Kannel, W.B., Ho, K.K., The progression from hypertension to congestive heart failure (1996) JAMA, 275, pp. 1557-1562Weber, K.T., Cardiac interstitium in health and disease: The fibrillar collagen network (1989) J Am Coll Cardiol, 13, pp. 1637-1652Frustaci, A., Caldarulo, M., Buffon, A., Bellocci, F., Fenici, R., Melina, D., Cardiac biopsy in patients with "primary" atrial fibrillation. Histologic evidence of occult myocardial diseases (1991) Chest, 100, pp. 303-306Ling, L.H., Kistler, P.M., Ellims, A.H., Diffuse ventricular fibrosis in atrial fibrillation: Noninvasive evaluation and relationships with aging and systolic dysfunction (2012) J Am Coll Cardiol, 60, pp. 2402-2408Diez, J., Querejeta, R., Lopez, B., Gonzalez, A., Larman, M., Martinez Ubago, J.L., Losartan-dependent regression of myocardial fibrosis is associated with reduction of left ventricular chamber stiffness in hypertensive patients (2002) Circulation, 105, pp. 2512-2517Kim, R.J., Fieno, D.S., Parrish, T.B., Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function (1999) Circulation, 100, pp. 1992-2002Mewton, N., Liu, C.Y., Croisille, P., Bluemke, D., Lima, J.A., Assessment of myocardial fibrosis with cardiovascular magnetic resonance (2011) J Am Coll Cardiol, 57, pp. 891-903Rudolph, A., Abdel-Aty, H., Bohl, S., Noninvasive detection of fibrosis applying contrast-enhanced cardiac magnetic resonance in different forms of left ventricular hypertrophy relation to remodeling (2009) J Am Coll Cardiol, 53, pp. 284-291Puntmann, V.O., Jahnke, C., Gebker, R., Usefulness of magnetic resonance imaging to distinguish hypertensive and hypertrophic cardiomyopathy (2010) Am J Cardiol, 106, pp. 1016-1022Brilla, C.G., Funck, R.C., Rupp, H., Lisinopril-mediated regression of myocardial fibrosis in patients with hypertensive heart disease (2000) Circulation, 102, pp. 1388-1393Querejeta, R., Lopez, B., Gonzalez, A., Increased collagen type i synthesis in patients with heart failure of hypertensive origin: Relation to myocardial fibrosis (2004) Circulation, 110, pp. 1263-1268Rossi, M.A., Pathologic fibrosis and connective tissue matrix in left ventricular hypertrophy due to chronic arterial hypertension in humans (1998) J Hypertens, 16, pp. 1031-1041Jerosch-Herold, M., Sheridan, D.C., Kushner, J.D., Cardiac magnetic resonance imaging of myocardial contrast uptake and blood flow in patients affected with idiopathic or familial dilated cardiomyopathy (2008) Am J Physiol Heart Circ Physiol, 295, pp. 1234-H1242Broberg, C.S., Chugh, S.S., Conklin, C., Sahn, D.J., Jerosch-Herold, M., Quantification of diffuse myocardial fibrosis and its association with myocardial dysfunction in congenital heart disease (2010) Circ Cardiovasc Imaging, 3, pp. 727-734Flett, A.S., Hayward, M.P., Ashworth, M.T., Equilibrium contrast cardiovascular magnetic resonance for the measurement of diffuse myocardial fibrosis: Preliminary validation in humans (2010) Circulation, 122, pp. 138-144Ugander, M., Oki, A.J., Hsu, L.Y., Extracellular volume imaging by magnetic resonance imaging provides insights into overt and sub-clinical myocardial pathology (2012) Eur Heart J, 33, pp. 1268-1278Iles, L., Pfluger, H., Phrommintikul, A., Evaluation of diffuse myocardial fibrosis in heart failure with cardiac magnetic resonance contrast-enhanced T1 mapping (2008) J Am Coll Cardiol, 52, pp. 1574-1580Wong, T.C., Piehler, K., Meier, C.G., Association between extracellular matrix expansion quantified by cardiovascular magnetic resonance and short-term mortality (2012) Circulation, 126, pp. 1206-1216Coelho-Filho, O.R., Mongeon, F.P., Mitchell, R., The role of transcytolemmal water exchange in magnetic resonance measurements of diffuse myocardial fibrosis in hypertensive heart disease (2013) Circ Cardiovasc Imaging, 6, pp. 134-141Chobanian, A.V., Bakris, G.L., Black, H.R., The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 report (2003) JAMA, 289, pp. 2560-2572Levy, D., Labib, S.B., Anderson, K.M., Christiansen, J.C., Kannel, W.B., Castelli, W.P., Determinants of sensitivity and specificity of electrocardiographic criteria for left ventricular hypertrophy (1990) Circulation, 81, pp. 815-820Mongeon, F.P., Jerosch-Herold, M., Coelho-Filho, O.R., Blankstein, R., Falk, R.H., Kwong, R.Y., Quantification of extracellular matrix expansion by CMR in infiltrative heart disease (2012) J Am Coll Cardiol Img, 5, pp. 897-907Neilan, T.G., Coelho-Filho, O.R., Shah, R.V., Myocardial extracellular volume fraction from T1 measurements in healthy volunteers and mice: Relationship to aging and cardiac dimensions (2013) J Am Coll Cardiol Img, 6, pp. 672-683Ho, C.Y., Abbasi, S.A., Neilan, T.G., T1 measurements identify extracellular volume expansion in hypertrophic cardiomyopathy sarcomere mutation carriers with and without left ventricular hypertrophy (2013) Circ Cardiovasc Imaging, 6, pp. 415-422Cleland, J.G., Daubert, J.C., Erdmann, E., The effect of cardiac resynchronization on morbidity and mortality in heart failure (2005) N Engl J Med, 352, pp. 1539-1549Tsang, T.S., Gersh, B.J., Appleton, C.P., Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women (2002) J Am Coll Cardiol, 40, pp. 1636-1644Vaziri, S.M., Larson, M.G., Benjamin, E.J., Levy, D., Echocardiographic predictors of nonrheumatic atrial fibrillation the Framingham Heart Study (1994) Circulation, 89, pp. 724-730Kuwahara, F., Kai, H., Tokuda, K., Transforming growth factor-beta function blocking prevents myocardial fibrosis and diastolic dysfunction in pressure-overloaded rats (2002) Circulation, 106, pp. 130-135Shinbane, J.S., Wood, M.A., Jensen, D.N., Ellenbogen, K.A., Fitzpatrick, A.P., Scheinman, M.M., Tachycardia-induced cardiomyopathy: A review of animal models and clinical studies (1997) J Am Coll Cardiol, 29, pp. 709-715He, X., Gao, X., Peng, L., Atrial fibrillation induces myocardial fibrosis through angiotensin II type 1 receptor-specific Arkadia-mediated downregulation of Smad7 (2011) Circ Res, 108, pp. 164-175Swartz, M.F., Fink, G.W., Sarwar, M.F., Elevated pre-operative serum peptides for collagen i and iii synthesis result in post-surgical atrial fibrillation (2012) J Am Coll Cardiol, 60, pp. 1799-1806Dahlof, B., Devereux, R.B., Kjeldsen, S.E., Cardiovascular morbidity and mortality in the Losartan Intervention for Endpoint reduction in hypertension study (LIFE): A randomised trial against atenolol (2002) Lancet, 359, pp. 995-1003Levy, D., Garrison, R.J., Savage, D.D., Kannel, W.B., Castelli, W.P., Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study (1990) N Engl J Med, 322, pp. 1561-1566Bluemke, D.A., Kronmal, R.A., Lima, J.A., The relationship of left ventricular mass and geometry to incident cardiovascular events: The MESA (Multi-Ethnic Study of Atherosclerosis) study (2008) J Am Coll Cardiol, 52, pp. 2148-2155Anversa, P., Ricci, R., Olivetti, G., Quantitative structural analysis of the myocardium during physiologic growth and induced cardiac hypertrophy: A review (1986) J Am Coll Cardiol, 7, pp. 1140-1149Gardin, J.M., Arnold, A., Gottdiener, J.S., Left ventricular mass in the elderly the Cardiovascular Health Study (1997) Hypertension, 29, pp. 1095-1103Armstrong, A.C., Gidding, S., Gjesdal, O., Wu, C., Bluemke, D.A., Lima, J.A., LV mass assessed by echocardiography and CMR, cardiovascular outcomes, and medical practice (2012) J Am Coll Cardiol Img, 5, pp. 837-848Lang, R.M., Bierig, M., Devereux, R.B., Recommendations for chamber quantification: A report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology (2005) J Am Soc Echocardiogr, 18, pp. 1440-1463Missouris, C.G., Forbat, S.M., Singer, D.R., Markandu, N.D., Underwood, R., MacGregor, G.A., Echocardiography overestimates left ventricular mass: A comparative study with magnetic resonance imaging in patients with hypertension (1996) J Hypertens, 14, pp. 1005-1010MacEira, A.M., Prasad, S.K., Khan, M., Pennell, D.J., Normalized left ventricular systolic and diastolic function by steady state free precession cardiovascular magnetic resonance (2006) J Cardiovasc Magn Reson, 8, pp. 417-426Messroghli, D.R., Radjenovic, A., Kozerke, S., Higgins, D.M., Sivananthan, M.U., Ridgway, J.P., Modified Look-Locker inversion recovery (MOLLI) for high-resolution T1 mapping of the heart (2004) Magn Reson Med, 52, pp. 141-146Lee, J.J., Liu, S., Nacif, M.S., Myocardial T1 and extracellular volume fraction mapping at 3 tesla (2011) J Cardiovasc Magn Reson, 13, p. 75Polimeni, P.I., Extracellular space and ionic distribution in rat ventricle (1974) Am J Physiol, 227, pp. 676-683Jellis, C., Wright, J., Kennedy, D., Association of imaging markers of myocardial fibrosis with metabolic and functional disturbances in early diabetic cardiomyopathy (2011) Circ Cardiovasc Imaging, 4, pp. 693-702Flett, A.S., Sado, D.M., Quarta, G., Diffuse myocardial fibrosis in severe aortic stenosis: An equilibrium contrast cardiovascular magnetic resonance study (2012) Eur Heart J Cardiovasc Imaging, 13, pp. 819-826Schneider, M.P., Hua, T.A., Bohm, M., Wachtell, K., Kjeldsen, S.E., Schmieder, R.E., Prevention of atrial fibrillation by renin-angiotensin system inhibition: A meta-analysis (2012) J Am Coll Cardiol, 55, pp. 2299-2307Yusuf, S., Teo, K., Anderson, C., Effects of the angiotensin-receptor blocker telmisartan on cardiovascular events in high-risk patients intolerant to angiotensin-converting enzyme inhibitors: A randomised controlled trial (2008) Lancet, 372, pp. 1174-118

The Incidence, Pattern, and Prognostic Value of Left Ventricular Myocardial Scar by Late Gadolinium Enhancement in Patients With Atrial Fibrillation

Cardiovascular Aspects of Radiolog