Um novo índice de doppler tecidual para a predição de fibrilação atrial futura em pacientes com insuficiência cardíaca / A new tissue doppler index in predicting future atrial fibrillation in patients with heart failure

FUNDAMENTO: O aparecimento de Fibrilação Atrial (FA) em pacientes com Insuficiência Cardíaca (IC) está em geral associado a uma alta ocorrência de complicações cardiovasculares. Constatou-se que a relação E/(E' × S') (E = velocidade transmitral diastólica inicial, E' = velocidade diastólica inicial no anel mitral e S = velocidade sistólica no anel mitral) reflete a pressão de enchimento do ventrículo esquerdo. Objetivo: Investigamos se E/(E' × S') poderia ser um preditor de FA de início recente em pacientes com IC. MÉTODOS: Foram analisados 113 pacientes consecutivos hospitalizados com IC, em ritmo sinusal, após o tratamento médico adequado. Os pacientes com histórico de FA, imagens ecocardiográficas inadequadas, cardiopatia congênita, ritmo acelerado, doença valvar primária significativa, síndrome coronariana aguda, revascularização coronária durante o seguimento, doença pulmonar ou insuficiência renal grave não foram incluídos. E/(E' × S') foi determinado utilizando a média das velocidades das bordas septal e lateral do anel mitral. A meta principal do estudo foi a FA de início recente. RESULTADOS: Durante o período de seguimento (35,7 ± 11,2 meses), 33 pacientes (29,2 por cento) desenvolveram FA. A média de E/(E' × S') foi de 3,09 ± 1,12 nesses pacientes, ao passo que foi de 1,72 ± 1,34 no restante (p < 0,001). O corte de relação E/(E' × S') ótima para predizer FA de início recente foi de 2,2 (88 por cento de sensibilidade, 77 por cento de especificidade). Havia 64 pacientes (56,6 por cento) com E/(E' × S') < 2,2 e 49 (43,4 por cento) com E/(E '× S') > 2,2. A FA de início recente foi maior em pacientes com E/(E' × S') > 2,2 que em pacientes com E/(E' × S') < 2,2 [29 (59,1 por cento) versus 4 (6,2 por cento), p < 0,001]. Na análise multivariada de Cox incluindo as variáveis que previram FA em análise univariada, a relação E/(E' × S') foi o único preditor independente de FA de início recente (relação de risco = 2,26, 95 por cento de intervalo de confiança = 1,25 - 4,09, p = 0,007). CONCLUSÃO: Em pacientes com IC, a relação E/(E' × S') parece ser um bom preditor de FA de início recente.

BACKGROUND: Onset of atrial fibrillation (AF) in patients with heart failure (HF) is usually associated with a high occurrence of cardiovascular complications. E/(E'×S') ratio (E=early diastolic transmitral velocity, E'=early mitral annular diastolic velocity and S'=systolic mitral annulus velocity) has been shown to reflect left ventricular filling pressure. OBJECTIVE: We investigate whether E/(E'×S') could be a predictor of new-onset AF in patients with HF. METHODS: We analyzed 113 consecutive hospitalized patients with HF, in sinus rhythm, after appropriate medical treatment. Patients with histories of AF, inadequate echocardiographic images, congenital heart disease, paced rhythm, significant primary valvular disease, acute coronary syndrome, coronary revascularization during follow-up, severe pulmonary disease or renal failure were not included. E/(E'×S') was determined using the average of septal and lateral mitral annular velocities. The primary study end-point was the new-onset AF. RESULTS: During the follow-up period (35.7±11.2 months), 33 patients (29.2 percent) developed AF. Mean E/(E'×S') was 3.09±1.12 in these patients, while it was 1.72±1.34 in the other patients (p<0.001). The optimal E/(E'×S') cut-off to predict new-onset AF was 2.2 (88 percent sensitivity, 77 percent specificity). There were 64 patients (56.6 percent) with E/(E'×S')<2.2 and 49 (43.4 percent) with E/(E'×S')>2.2. New-onset AF was higher in patients with E/(E'×S')>2.2 than in patients with E/(E'×S')<2.2 [29 (59.1 percent) versus 4 (6.2 percent), p<0.001]. On multivariate Cox analysis including the variables that predicted AF on univariate analysis, E/(E'×S') was the only independent predictor of new-onset AF (hazard ratio=2.26, 95 percent confidence interval=1.25-4.09, p=0.007). CONCLUSION: In patients with HF, E/(E'×S') seems to be a good predictor of new-onset AF.

Additive value of torsion to global longitudinal left ventricular strain in patients with reduced ejection fraction.

BACKGROUND: Torsional and longitudinal deformations are essential components of left ventricular (LV) performance. A precise assessment of LV function must take into account both LV torsion (LVtor) and global longitudinal strain (LVE). We compared a new 2D-strain parameter, LVtor x LVE, with several other echocardiographic parameters, with respect to their strength of association with N-terminal pro-brain natriuretic peptide (NTproBNP) in patients with reduced LV ejection fraction (LVEF). METHODS: Echocardiography was performed simultaneously with NTproBNP determination in 78 consecutive patients with reduced LVEF (<50%) in sinus rhythm. Early diastolic transmitral velocity/early mitral annular diastolic velocity ratio (E/E') and systolic mitral annular velocity (S') were measured. LVtor was defined as the ratio between LV twist (LVtw) and LV end-diastolic longitudinal length. LVtw (net difference between rotation angles at base and apex) was obtained from parasternal apical and basal short-axis planes. LVE was obtained by averaging longitudinal peak systolic strain of all 17 LV-segments (from apical planes). RESULTS: Log-transformed NTproBNP correlated significantly with LVE (r = 0.57, P < 0.001), myocardial performance index (r = 0.56, P < 0.001), systolic pulmonary artery pressure (r = 0.47, P < 0.001), E/E' (r = 0.41, P < 0.001), LVtor (r = -0.37, P = 0.001), E-velocity deceleration time (r = -0.37, P = 0.003), S' (r = -0.36, P = 0.002), LVtw (r = -0.34, P = 0.003), LVEF (r = -0.34, P = 0.003), E/A (A = late diastolic transmitral velocity, r = 0.30, P = 0.01) and E (r = 0.28, P = 0.03). LVtor x LVepsilon had the strongest correlation with log-NTproBNP (r = 0.70, P < 0.001). LVtor x LVepsilon was a better predictor of NTproBNP > 900 pg/ml (sensitivity = 82%, specificity = 84%) than other investigated parameters (each P < 0.05). CONCLUSIONS: In patients with reduced LVEF, LVtor x LVE is a promising parameter that deserves research to establish its clinical meaning and prognostic value.

A new tissue doppler index in predicting future atrial fibrillation in patients with heart failure.

BACKGROUND: Onset of atrial fibrillation (AF) in patients with heart failure (HF) is usually associated with a high occurrence of cardiovascular complications. E/(E'×S') ratio (E=early diastolic transmitral velocity, E'=early mitral annular diastolic velocity and S'=systolic mitral annulus velocity) has been shown to reflect left ventricular filling pressure. OBJECTIVE: We investigate whether E/(E'×S') could be a predictor of new-onset AF in patients with HF. METHODS: We analyzed 113 consecutive hospitalized patients with HF, in sinus rhythm, after appropriate medical treatment. Patients with histories of AF, inadequate echocardiographic images, congenital heart disease, paced rhythm, significant primary valvular disease, acute coronary syndrome, coronary revascularization during follow-up, severe pulmonary disease or renal failure were not included. E/(E'×S') was determined using the average of septal and lateral mitral annular velocities. The primary study end-point was the new-onset AF. RESULTS: During the follow-up period (35.7±11.2 months), 33 patients (29.2%) developed AF. Mean E/(E'×S') was 3.09±1.12 in these patients, while it was 1.72±1.34 in the other patients (p<0.001). The optimal E/(E'×S') cut-off to predict new-onset AF was 2.2 (88% sensitivity, 77% specificity). There were 64 patients (56.6%) with E/(E'×S')<2.2 and 49 (43.4%) with E/(E'×S')>2.2. New-onset AF was higher in patients with E/(E'×S')>2.2 than in patients with E/(E'×S')<2.2 [29 (59.1%) versus 4 (6.2%), p<0.001]. On multivariate Cox analysis including the variables that predicted AF on univariate analysis, E/(E'×S') was the only independent predictor of new-onset AF (hazard ratio=2.26, 95% confidence interval=1.25-4.09, p=0.007). CONCLUSION: In patients with HF, E/(E'×S') seems to be a good predictor of new-onset AF.

The relationship between the time interval difference of isovolumic relaxation (T[IVRT-IVRTa]) and serum levels of N-terminal pro-brain natriuretic peptide in patients with intermediate E/Ea ratio.

INTRODUCTION: The ratio of early diastolic transmitral velocity to early mitral annular diastolic velocity (E/Ea) can be used to group patients according to filling pressures. However this relationship has not been validated in the intermediate group (E/Ea = 8-15). The time difference between the onset of E and Ea also correlates with left ventricular (LV) filling pressures. The purpose of our study was to evaluate the correlation between the time interval difference of isovolumic relaxation (T[IVRT-IVRTa]) and N-terminal pro-brain natriuretic peptide (NTpro-BNP) in patients with an intermediate E/Ea ratio. METHODS: Echocardiography was performed simultaneously with NTpro-BNP measurement in 60 consecutive patients who had an intermediate E/Ea and were in sinus rhythm. Ea and the isovolumic relaxation time (IVRTa) at the septal and lateral sites of the mitral annulus were measured using pulsed tissue Doppler and the average was utilised. Pulsed Doppler was used to measure E and IVRT. E/Ea and IVRT-IVRTa (T[IVRT-IVRTa]) were calculated. RESULTS: We demonstrated significant correlations between T[IVRT-IVRTa] and NTpro-BNP (r = -0.72, p<0.001), maximal systolic velocity of the mitral annulus (Sa: r = -0.50, p < 0.001), pulmonary artery systolic pressure (r = 0.42, p = 0.002), IVRTa (r = -0.27, p = 0.03), LV ejection fraction (LVEF: r = -0.26, p = 0.04), IVRT (r = -0.24, p = 0.04). We were unable to demonstrate significant relationships between NTpro-BNP and E deceleration time, left atrial diameter/area/volume, Ea or E. By a multiple linear regression analysis, including T[IVRT-IVRTa], IVRT, IVRTa, E/Ea, LVEF, pulmonary artery systolic pressure and Sa as potential determinants, TIVRT-IVRTa (= -0.57, p < 0.001) was shown to be the best independent predictor of NTpro-BNP (r 2 = 0.68, p < 0.001). CONCLUSIONS: T[IVRT-IVRTa] correlates strongly with NTpro-BNP levels in patients with intermediate E/Ea, and could be used as a simple echocardiographic index, with reasonable accuracy.

E/(EaxSa) estimates left ventricular end-diastolic pressure in patients with severe mitral regurgitation.

BACKGROUND AND AIM OF THE STUDY: The early diastolic transmitral velocity/early mitral annular diastolic velocity ratio (E/Ea) reflects left ventricular (LV) filling pressure in a variety of cardiac diseases. The value of this parameter in patients with significant mitral regurgitation (MR) remains controversial. It has been hypothesized that, by combining the index of diastolic function (E/Ea) and a parameter that explores LV systolic performance (Sa, mitral annulus peak systolic velocity), a close prediction of the LV end-diastolic pressure (LVEDP) can be provided. Hence, the study aim was to assess the relationship between a new parameter, E/(EaxSa), and LVEDP in patients with severe MR. METHODS: A total of 55 consecutive patients with severe MR, in sinus rhythm, who had been referred for heart catheterization, was analyzed. Echocardiography was performed simultaneously with LVEDP measurements. Both, E/Ea and E/(EaxSa) were calculated, using the average of the velocities of the septal and lateral mitral annulus. RESULTS: A significant linear correlation was demonstrated between E/(EaxSa) and LVEDP (r = 0.81, p < 0.001); this was superior to E/Ea (r = 0.73, p < 0.001), Sa (r = -0.59, p = 0.004), pulmonary artery systolic pressure (r = 0.57, p = 0.007), E-wave (r = 0.45, p = 0.009), Ea (r = -0.31, p = 0.01), and left atrial volume (r = 0.28, p = 0.02). No significant relationships could be demonstrated between LVEDP and the LV ejection fraction. The area under the receiver-operating characteristic (ROC) curve for prediction of LVEDP > 15 mmHg was greatest for E/(EaxSa) (AUC = 0.87, p < 0.001), followed by the E/Ea ratio (AUC = 0.81, p < 0.001). A statistical comparison of the ROC curves indicated that E/(EaxSa) was more accurate than E/Ea (p = 0.02). The optimal E/(EaxSa) cut-off to predict a LVEDP > 15 mmHg was 1.95 (85% sensitivity, 83% specificity). CONCLUSION: E/(EaxSa) correlates strongly with LVEDP, and can serve as a simple and accurate echocardiographic index for the estimation of LVEDP in patients with severe MR.

A novel index combining diastolic and systolic Tissue Doppler parameters for the non-invasive assessment of left ventricular end-diastolic pressure.

BACKGROUND: Early diastolic transmitral velocity (E)/early mitral annular diastolic velocity (Ea) ratio has been proposed as the best Doppler predictor for evaluating left ventricular (LV) filling pressure. PURPOSE: To evaluate the relationship between a novel echocardiographic index, E/(EaxSa), and left ventricular end-diastolic pressure (LVEDP); Sa is the peak systolic mitral annular velocity. We measured this index at different sites of the mitral annulus and compared it with other Tissue Doppler parameters. METHODS: Echocardiography was performed simultaneously with left heart catheterization in 110 consecutive patients in sinus rhythm. E, Sa, Ea and Aa (late mitral annular diastolic velocity) were determined at medial and lateral site, and average values obtained. E/Ea and E/(EaxSa) were calculated (medial, lateral, average). LVEDP was measured with invasively fluid-filled catheter. RESULTS: We demonstrated significant correlations between LVEDP and E/(EaxSa)(lateral) (r=0.78, p<0.0001), E/Ea(average) (r=0.70, p<0.0001), E/Ea(lateral) (r=0.66, p<0.0001), E/Ea(medial) (r=0.60, p<0.0001) and E/(EaxSa)(medial) (r=0.60, p<0.0001). E/(EaxSa)(average) had the strongest correlation with LVEDP (r=0.80, p<0.0001). An E/(EaxSa)(average) cut-off of 1.6 had 86% sensitivity and 85% specificity for detecting LVEDP>15 mmHg. Weaker correlations were found for Sa, Ea and Aa. E/(EaxSa)(average) was the best parameter to assess LVEDP in patients with normal LV ejection fraction (LVEF>or=50%) (r=0.83, p<0.0001), depressed LVEF (r=0.76, p<0.0001), regional dysfunction (r=0.81, p<0.0001), or E/Ea(average) between 8 and 15 (r=0.67, p<0.0001). CONCLUSIONS: E/(EaxSa)(average) was the best predictor of LVEDP in sinus rhythm patients, regardless of LVEF, particularly in those with E/Ea(average) between 8 and 15 and in those with regional dysfunction.

Unusual cause of heart failure in a 65-year-old woman.

Left ventricular (LV) free wall rupture is a potentially lethal mechanical complication after myocardial infarction (MI). Pericardial adhesions or slow extracardiac leak and pericardial inflammation may result in a contained cardiac rupture. LV pseudoaneurysm is a relatively uncommon clinical entity. It may occur after MI, but also as a complication of infective endocarditis, cardiac surgery, or trauma. Patients developing LV pseudoaneurysm after MI may present angina pectoris or signs of congestive heart failure (HF) but often are asymptomatic. Surgery is the treatment of choice for LV pseudoaneurysms diagnosed in the first months after MI. The management of chronic LV pseudoaneurysms is still subject of debate. This report highlights a 65-year-old patient newly hospitalized for acute decompensated HF who was diagnosed with a large chronic LV pseudoaneurysm and severe mitral regurgitation. The patient underwent successful resection of the pseudoaneurysm and patch repair of the ruptured ventricular wall.

The relationship between tissue Doppler imaging and seric NTproBNP levels in sinus rhythm patients: a prospective study.

UNLABELLED: N-terminal pro-brain natriuretic peptide (NTproBNP) correlates with left ventricular (LV) filling pressure. The ratio between early diastolic transmitral velocity and early mitral annular diastolic velocity (E/Ea) reflects LV filling pressure in a variety of cardiac diseases. However this relationship was not validated in some categories of patients. Our aim was to evaluate the correlation between tissue Doppler velocities of the mitral annulus and NTproBNP levels in sinus rhythm patients. METHODS: Echocardiography was performed in 111 consecutive patients simultaneously with NTproBNP measurement. E/Ea and E/(Ea x Sa) were calculated (Sa is the maximal systolic velocity of mitral annulus); the average of the velocities of septal and lateral mitral annulus was used. RESULTS: Simple regression analysis demonstrated a significant linear correlation between E/(Ea x Sa) and NTproBNP (r = 0.71, P < 0.0001), superior to E/Ea correlation (r = 0.58, P < 0.0001). Significant but weaker correlations were found between NTproBNP and Sa, pulmonary artery systolic pressure, Ea, mitral E/A (early/late diastolic transmitral velocity), E wave, mitral E deceleration time and LV ejection fraction (LVEF). The optimal E/(Ea x Sa) cut-off for prediction of NTproBNP levels > 900 pg/ml was 1.5 (sensitivity = 81%, specificity = 70%). Among analyzed parameters, E/(Ea x Sa) was best correlated with NTproBNP levels in patients with LVEF >or= 50% (r = 0.80, P < 0.0001), with depressed LVEF (<50%) (r = 0.66, P < 0.0001), with regional wall motion abnormalities (r = 0.75, P < 0.0001), and with E/Ea 8 to 15 (r = 0.58, P < 0.0001). CONCLUSIONS: E/(Ea x Sa) strongly correlates with NTproBNP, regardless of LVEF, and can be a simple and accurate echocardiographic index in patients in sinus rhythm, particularly in those with regional wall motion abnormalities or intermediate E/Ea.

Left atrial remodeling: assessment of size and shape to detect vulnerability to atrial fibrillation.

BACKGROUND: The ellipse formula often underestimates left atrial (LA) dilation. Complete echocardiographic analysis of LA shape in relation to electrical remodeling has not been performed. AIM OF THE STUDY: To analyze the relation between LA shape/surface and vulnerability to atrial fibrillation (AF). METHODS: We studied 112 patients aged 43 +/- 16 years, and referred for electrophysiological study. LA surface (LAS) was measured at end-systole (maximal). Trapezoidal LA shape was defined if the transverse dimension was less than the basal dimension. Decremental index (DI) was calculated as the maximal percentage prolongation of interatrial conduction time during atrial extrastimulation. The LA was considered vulnerable if AF was inducible. DI > 50%, repetitive atrial activity, and fragmented electrograms defined susceptibility to vulnerability. RESULTS: LAS ranged between 10.5 and 36.6 cm(2); 77 patients had a trapezoidal LA. By simple regression analysis LAS correlated with DI (r(2) = 0.38, P = 0.0001). LAS predicted susceptibility to vulnerability better than vulnerability to AF (area under the ROC curve: 0.93 vs 0.81). The best cut-off value for LAS as predictor of susceptibility to vulnerability was 19.5 cm(2) (sensitivity: 89%; specificity: 90.5%; positive predictive value: 93.4%; negative predictive value: 84.4%). Using LAS > 25 cm(2) as a cut-off value, LA vulnerability to AF was detected with a sensitivity of 56.2% and a specificity of 95% (positive predictive value: 81.8%; negative predictive value: 83.3%). LA shape was trapezoidal in 72% patients with LAS > 25 cm(2) and in 30% patients with LAS < 19.5 cm(2) (P < 0.0001). CONCLUSIONS: LA dilation and electrical remodeling are related. Progressive LA dilation is accompanied by shape remodeling. Appropriate characterization of LA remodeling should therefore include LAS measurement and LA shape assessment.

Relationship between global myocardial index and automatic left ventricular border detection pattern to identify biventricular pacing candidates.

OBJECTIVE OF THE STUDY: to evaluate the relation between global myocardial index (GMI) and the pattern of left ventricular (LV) volume curves variation, using automatic border detection (ABD), and their role in assessing LV asynchrony. METHODS: We studied 52 patients (mean age = 55 +/- 17 years) with dilated cardiomyopathy. QRS duration (QRSd) and GMI were measured. Currently accepted TDI and M-mode parameters were used to indicate LV dyssynchrony. On-line continuous LV volume changes were recorded using ABD. Ejection time (ET ABD) was measured from the ABD wave-forms as time interval between maximal and minimal volume variation during LV electromechanical systole. We derived the ejection time index (ETiABD) as the ratio between ET ABD and RR interval (ETiABD = ET/RR). RESULTS: 31 patients had a QRSd > 120 ms and 21 patients had a QRSd < 120 ms. Ventricular dyssynchrony was observed in 39 patients (29 patients had a QRSd > 120 ms). GMI was significantly higher in patients with, than in patients without ventricular dyssynchrony (1.06 +/- 0.18 vs 0.73 +/- 0.13, P = 0.0001), while ETABD was significantly smaller (233 +/- 39 ms vs 321 +/- 28 ms, P = 0.0001). The corresponding difference for ETiABD was 26.9 +/- 6.8% vs 6.3 +/- 4%, P < 0.0001. By simple regression analysis an inverse linear correlation was observed between GMI and ETiABD (r(2) = -0.51, P < 0.0001). The pattern of ABD waveforms showed increased isovolumic contraction and relaxation times in patients with LV asynchrony, similar to the GMI pattern. CONCLUSIONS: Regional delays in ventricular activation cause uncoordinated and prolonged ventricular contractions, with lengthening of the isovolumic contraction and relaxation times and shortening of the time available for filling and ejection. GMI explores these parameters and together with ABD might be useful to identify patients with ventricular asynchrony.

Electrophysiological and echocardiographic parameters predisposing to atrial fibrillation in patients with a structurally normal heart.

BACKGROUND: The electroanatomical substrate of dilated atria is characterised by increased non-uniform anisotropy and macroscopic slowing of conduction, which promote reentrant circuits. AIM: To analyse the relationship between electrophysiological properties of atria and echocardiographic markers of dilatation and increased filling pressure. METHODS: The study group consisted of 79 patients without structural heart disease, aged 53+/-22 years, who were referred for electrophysiological study. In order to examine the atrial electrophysiological characteristics we studied interatrial conduction time (iaCT), double potentials and fragmented atrial activity during premature stimulation of the high right atrium (HRA). The analysed parameters included: duration of atrial activity, baseline iaCT (iaCTb) between HRA and distal coronary sinus (CS), iaCT during HRA pacing S1S1 600 ms (iaCTS1), maximum prolongation of iaCT during S2 and S3 delivery (iaCTS2, iaCTS3). We also calculated the decremental index (DI)=iaCT S3- iaCTS1/iaCTS1%. The following echocardiographic parameters were assessed: left atrial (LA) dimensions, surface (LAs), volume using ellipse formula (LAv), right surface (RAs), total atrial surface (TAs=LAs+RAs), and global myocardial index (GMI). RESULTS: Patients were divided into two groups. Group 1 consisted of 37 patients with evidence of slow atrial conduction (atrial fragmentation/iaCTb>80 ms/DI>50%/double atrial potentials), whereas group 2 was composed of 42 patients without slow conduction properties. There were no significant differences concerning age, body mass index or LA parasternal dimensions between the groups. Thirty-seven patients, of whom 32 were from group 1, had documented episodes of paroxysmal atrial fibrillation. GMI, LAs, LAv and TAs values were significantly higher in patients from group 1 than in group 2 subjects. A statistically significant linear correlation between iaCTb and TAs (r=0.52 p <0.0001)/LAv (r=0.38 p <0.0001) was found. There was also a trend toward a correlation between DI and TAs. CONCLUSION: This study supports the role of stretch and dilated atria in electrophysiological changes which occur in structurally normal hearts. The iaCT value may be indirectly and non-invasively evaluated using echocardiographic measurements.

Mechanism of atrial fibrillation: decremental conduction, fragmentation, and ectopic activity in patients with drug resistance paroxysmal atrial fibrillation and structurally normal heart.

Atrial fibrillation (AF) has been associated with premature beats and decreased atrial conduction velocity. This study examined a new index of dynamic inter-atrial conduction time (iaCT) in patients with paroxysmal AF (PAF). We compared 42 consecutive patients with paroxysmal AF (mean age = 52 +/- 16 years) without structural heart disease with 39 age-matched patients (mean age = 49 +/- 15 years) who underwent ablation of junctional tachycardias. Prior to investigation, all antiarrhythmic drugs were discontinued for an appropriate period of time. The following measurements were made: baseline iaCT (iaCTb) between high right atrium (HRA) and distal coronary sinus, iaCT during HRA pacing S1S1 600 ms (iaCTS1), maximum prolongation of iaCT during S2 and S3 delivery (iaCTS2, iaCTS3). We then derived the decremental index (DI), the maximum percent prolongation of iaCT = iaCT S3-iaCTS1/iaCTS1%. In patients with PAF, iaCTb was 81.3 +/- 24 ms versus 59.5 +/- 14 ms in controls (P = 0.0001). Atrial fibrillation was reproducibly and easily induced with a prominent increase in iaCT in 11 patients with AF. In this subgroup DI was 92 +/- 17%, compared to 45 +/- 21% in the other patients with AF (P = 0.0001) and 21 +/- 15% in the control group (P = 0.0001). Spontaneous isolated or repetitive ectopic activity was observed in 11 patients with AF (26%), and decremental atrial conduction was observed in 76% of patients with AF. This study supports the role of dynamic inter-atrial conduction disturbances in patients with lone PAF. The DI may be a new index of vulnerability to paroxysmal AF.

Can simple Doppler measurements estimate interatrial conduction time?

UNLABELLED: Prolongation of the interatrial conduction time (ia-CT) is considered an important factor in the pathophysiology of atrial fibrillation (AF) and as a criterion to perform multisite atrial pacing. Measurement of ia-CT requires an electrophysiologic study. The aim of this study was to compare echocardiographic with electrophysiologic measurements to determine if they are correlated. METHODS AND RESULTS: The study included 32 consecutive patients who underwent electrophysiologic studies. We measured ia-CT between the high right atrium and the distal coronary sinus. In all patients we measured P wave duration, left atrial diameter and area, and ia-CT by Doppler echocardiography was measured as the difference in time intervals between the QRS onset and the tricuspid A wave, and the QRS onset and the mitral A wave (DT). Ia-CT was statistically correlated with DT (r = 0.79, P < 0.0001), but not with P wave duration or left atrial dimensions. CONCLUSIONS: Measurement DT may be reliable to estimate ia-CT without invasive procedure. Accordingly, DT could be used as a simple selection criterion when considering patients for atrial resynchronization therapy.