Screening for Cardiac Magnetic Resonance Scar Features by 12-Lead ECG, in Patients with Preserved Ejection Fraction.

BACKGROUND: Increased QRS score and wide spatial QRS-T angle are independent predictors of cardiovascular mortality in the general population. Our main objective was to assess whether a QRS score ≥ 5 and/or QRS-T angle ≥ 105° enable screening of patients for myocardial scar features. METHODS: Seventy-seven patients of age ≤ 70 years with QRS score ≥ 5 and/or spatial QRS-T angle ≥ 105° as well as left ventricular ejection fraction (LVEF) >35% were enrolled in the study. All participants underwent complete clinical examination, signal-averaged ECG (SAECG), 30-minute ambulatory ECG recording for T-wave alternans (TWA), and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Relationship between QRS score, QRS-T angle with scar presence and pattern, as well as gray zone, core, and total scar size by LGE-CMR were assessed. RESULTS: Myocardial scar was present in 41 (53%) patients, of whom 19 (46%) exhibited a typical ischemic pattern. QRS score but not QRS-T angle was related to total scar size and gray zone size (R(2) = 0.12, P = 0.002; R(2) = 0.17; P ≤ 0.0001, respectively). Patients with QRS scores ≥ 6 had significantly greater myocardial scar and gray zone size, increased QRS duration and QRS-T angle, a higher prevalence of late potentials (LPs) presence, increased LV end-diastolic volume and decreased LVEF. There was a significant independent and positive association between TWA value and total scar (P = 0.001) and gray zone size (P = 0.01). CONCLUSION: Patients with preserved LVEF and myocardial scar by CMR also have electrocardiographic features that could be involved in ventricular arrhythmogenesis.

Associations of electrocardiographic P-wave characteristics with left atrial function, and diffuse left ventricular fibrosis defined by cardiac magnetic resonance: The PRIMERI Study.

BACKGROUND: Abnormal P-terminal force in lead V1 (PTFV1) is associated with an increased risk of heart failure, stroke, atrial fibrillation, and death. OBJECTIVE: Our goal was to explore associations of left ventricular (LV) diffuse fibrosis with left atrial (LA) function and electrocardiographic (ECG) measures of LA electrical activity. METHODS: Patients without atrial fibrillation (n = 91; mean age 59.5 years; 61.5% men; 65.9% white) with structural heart disease (spatial QRS-T angle ≥105° and/or Selvester QRS score ≥5 on ECG) but LV ejection fraction >35% underwent clinical evaluation, cardiac magnetic resonance, and resting ECG. LA function indices were obtained by multimodality tissue tracking using 2- and 4-chamber long-axis images. T1 mapping and late gadolinium enhancement were used to assess diffuse LV fibrosis and presence of scar. P-prime in V1 amplitude (PPaV1) and duration (PPdV1), averaged P-wave-duration, PR interval, and P-wave axis were automatically measured using 12 SLTM algorithm. PTFV1 was calculated as a product of PPaV1 and PPdV1. RESULTS: In linear regression after adjustment for demographic characteristics, body mass index, maximum LA volume index, presence of scar, and LV mass index, each decile increase in LV interstitial fibrosis was associated with 0.76 mV*ms increase in negative abnormal PTFV1 (95% confidence interval [CI] -1.42 to -0.09; P = .025), 15.3 ms prolongation of PPdV1 (95% CI 6.9 to 23.8; P = .001) and 5.4 ms prolongation of averaged P-duration (95% CI 0.9-10.0; P = .020). LV fibrosis did not affect LA function. PPaV1 and PTFV1 were associated with an increase in LA volumes and decrease in LA emptying fraction and LA reservoir function. CONCLUSION: LV interstitial fibrosis is associated with abnormal PTFV1, prolonged PPdV1, and P-duration, but does not affect LA function.

Number of P-wave fragmentations on P-SAECG correlates with infiltrated atrial fat.

BACKGROUND: Although atrial fibrillation (AF) triggers are known, the underlying AF substrate is less well understood. The goal of our study was to explore correlations between electrophysiological and structural characteristics of atria in patients with paroxysmal AF and individuals at AF risk. METHODS: Patients in sinus rhythm (N = 90; age 57 ± 10 year; 55 men [63.2%]) with structural heart disease and paroxysmal AF (n = 12 [13%]), or with AF risk factors and LVEF > 35% (n = 78), underwent SAECG and cardiac magnetic resonance study. Interatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. All local P-wave extrema were identified on SAECG leads during sinus rhythm. A P-wave fragmentation (Pf) was defined as an absolute difference between adjacent extrema which was above three standard deviations of noise, and was normalized by the duration of the P wave in the corresponding lead. RESULTS: The Pf was greater on the filtered than on the unfiltered P-SAECG signal (13.1 ± 3.8 vs. 3.4 ± 1.2; P < 0.0001). Pf was the greatest on the Y lead (13.0 ± 3.5 on Y lead vs. 12.1 ± 3.4 on Z lead; P = 0.003. Pf on Z lead correlated with interatrial fat index (r = 0.544; P = 0.001). Epicardial fat significantly correlated with body mass index (BMI; r = 0.302; P = 0.015). After adjustment for BMI, left atrium (LA) size, epicardial fat, and interatrial septum width, interatrial fat independently associated with the Pf on Z lead (ß-coefficient 0.009 [95%CI 0.0003-0.019]; P = 0.043). CONCLUSIONS: Infiltrated atrial fat correlates with discontinuous conduction on posterior LA wall and represents AF early substrate.

Infiltrated atrial fat characterizes underlying atrial fibrillation substrate in patients at risk as defined by the ARIC atrial fibrillation risk score.

BACKGROUND: It is known that expanded epicardial fat is associated with atrial fibrillation (AF). However, infiltrated intraatrial fat has not been previously quantified in individuals at risk as determined by the ARIC AF risk score. METHODS: Patients in sinus rhythm (N=90, age 57 ± 10 years; 55 men [63.2%]), in 3 groups at risk of AF as determined by the ARIC AF risk score [low (≤ 11 points; n=15), moderate (12-18 points; n=40), high (≥ 19 points; n=23) risk of AF], and paroxysmal AF (n=12) underwent cardiac magnetic resonance study. Intraatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. OsiriX DICOM viewer (Geneva, Switzerland) was used to quantify the intraatrial fat area. Width of the cephalad portion of the interatrial septum was measured at the level of the fossa ovalis. RESULTS: Intraatrial fat monotonically increased with growing AF risk in study groups (low AF risk 16 ± 4 vs. moderate AF risk 32 ± 18 vs. high AF risk 81 ± 83 mm(2); ANOVA P=0.012). Log-transformed intraatrial fat predicted ARIC AF risk score in multivariate ordered probit regression after adjustment for sex, race, left and right atrial area indices, and body mass index (ß-coefficient 0.50 [95% CI 0.03-0.97]; P=0.037), whereas epicardial fat did not. Interatrial septum width showed similar association (3.0 ± 1.4 vs. 5.0 ± 1.8 vs. 7.1 ± 2.7 mm; ANOVA P<0.001; adjusted ß-coefficient 2.80 [95% CI 1.19-4.41]; P=0.001). CONCLUSIONS: Infiltrated intraatrial fat characterizes evolving substrate in individuals at risk of AF.

Fatores associados à menor dose de radiação em pacientes submetidos à angiotomografia de artérias coronárias de 64 canais / Factors associated with lower radiation doses in patients undergoing 64-slice computed tomography

Fundamentos: Nota-se crescente utilização da angiotomografia de arterias coronárias, encontrando-se na literatura grande variabilidade na dose de radiação empregada. Há preocupação mundial em relação à exposição à radiação ionizante em procedimentos médicos, sendo que estratégias para minimização da dose são fortemente encorajadas. Objetivos: Determinar a dose de radiação utilizada em clínica privada no Rio de Janeiro e fatores associados à redução da dose. Métodos: Estudos retrospectivo e observacional, envolvendo 232 pacientes consecutivos submetidos à angiotomografia de artérias coronárias de 64 detectores por indicação clínica, utilizando-se técnicas visando à redução da dose de radiação. Resultados: A dose média geral de radiação empregada foi 7,6mSv, sem diferença na dose aplicada em homens e mulheres (7,9mSv vs. 7,0mSv, respectivamente, p=0,15). A utilização de modulação de dose pelo eletrocardiograma (ECG) e tensão do tubo de 100kV estão ambas associadas à queda de aproximadamente 50 por cento cada na dose. Fatores como idade avançada e presença de stents estão associados à maior exposição. Conclusões: A dose de radiação utilizada rotineiramente...

Background: In parallel to an upsurge in the use of computed tomography coronary angiography (CTCA), the literature varies widely in terms of radiation doses, prompting worldwide concern about radiation exposure in medical procedures, with strong supportfor strategies aimed at reducing these doses. Objectives: To determine the radiation dose employed in CTCA studies in a private clinic at Rio de Janeiro, Brazil, and the factors associated with lower radiation doses. Methods: Retrospective observational study of 232consecutive patients clinically referred for 64-slice CTCA with radiation dose r eduction techniques. Results: The mean radiation dose was 7.6mSv, with no difference between men and women (7.9mSv vs. 7.0mSv, respectively, p=0,15). Electrocardiogram (ECG) dose modulation and reduced 100kV tubevoltage are associated with dose reductions of approximately 50% each. Factors such as increasing age and the presence of coronary stents are associated with higher exposure. Conclusions: The routine radiation dose used with exposure minimization techniques...

Obtaining cornea donation consent by telephone.

BACKGROUND: Cornea donation process comes up against difficulties in obtaining families' consent. A face-to-face interview is often not possible for logistical reasons. We carried out a prospective study of the effectiveness of telephone contact in obtaining donation consent. METHODS: Consent was obtained by a single, nonmedical, hospital coordinator. If a face-to-face interview was not possible, a telephone interview was conducted using a standardized procedure. RESULTS: Over a 21-month period, 334 families were contacted, either in a face-to-face interview (142, 42.5%) or by telephone (192, 57.5%). Donation consent was obtained in 66.5% of cases, 106 times by telephone and 116 times in face-to-face interview. The acceptance rate was 55.2% by telephone and 81.6% face to face (P<0.001). In total, 47.7% of the cornea recovery consents were obtained after telephone interview. CONCLUSIONS: Telephone interview is an effective method for obtaining consent to cornea donation. Although the acceptance rate using this method is lower than by face-to-face interview, using the telephone should not be overlooked as this enabled procurement of nearly half the corneas in our hospital.