Decreasing operators' radiation exposure during coronary procedures: the transradial radiation protection board.

AIM: Transradial coronary procedures are associated with decreased vascular access site complications and other benefits compared to the femoral approach. There is some concern however about high-recorded radiation doses for interventional cardiologists using the transradial route. We therefore designed and investigated the effect of a transradial radiation protection board (TRPB) on operator radiation exposure during coronary procedures. METHODS AND RESULTS: One hundred and six patients were randomly assigned by time period to undergo radial coronary procedures either with or without a TRPB. This is a grooved arm board with a detachable 0.5-mm lead equivalent shield designed to rest between the patient's arm and side. Individual case-specific radiation exposures were measured using electronic personal dosimeter worn on the left outer pocket of the lead apron at chest level. The TRPB was used in addition to standard lead apron and thyroid shielding, below-table leaded flaps, and leaded glass. Operator radiation exposure was significantly decreased in the TRPB group overall: 28 [18-65] microSV versus 19.5 [10.5-35] microSV, P = 0.003. There were no significant differences in procedure duration, total fluoroscopy dose, or contrast load between the two groups. conclusion: Identification of methods to reduce operator radiation dose is important. The use of the TRPB can significantly reduce radiation exposure to radial operators.

Heart block: a primary manifestation of sarcoidosis.

We present the case of a 55-year-old male who presented with symptoms of dyspnoea and pre-syncope. A 12 lead electrocardiogram demonstrated extensive conduction abnormalities with 2:1 heart block, right bundle branch block and a small Q wave in lead V(1.) This indicated significant myocardial and septal involvement. Echocardiography confirmed the presence of right ventricular infiltration and dysfunction whilst cardiac magnetic resonance showed the infiltration to be nodular in nature. Although a diagnosis of cardiac sarcoidosis and lymphoma were initially considered, sarcoidosis was eventually confirmed following a cervical lymph node biopsy. This case firstly demonstrates the usefulness of the 12-lead electrocardiogram in determining the likely anatomical locality of significant bradyarrhythmias. Secondly it highlights the difficulties in diagnosing cardiac sarcoidosis when cardiac dysfunction is the sole manifestation of the disease.

Heart rate turbulence-based predictors of fatal and nonfatal cardiac arrest (The Autonomic Tone and Reflexes After Myocardial Infarction substudy).

A previous report on heart rate (HR) turbulence showed its value in postinfarction risk stratification. The present study determines the predictive value of HR turbulence in a low-risk population after acute myocardial infarction and provides insight into its pathophysiologic correlates. With use of the database of the The Autonomic Tone and Reflexes After Myocardial Infarction (ATRAMI) study, data were obtained from 1,212 survivors with a mean duration of follow-up of 20.3 months. The a priori end point was defined as the combination of fatal cardiac arrest and nonfatal cardiac arrest. HR turbulence characterized by turbulence onset (TO) and turbulence slope (TS) was calculated and correlated with baroreflex sensitivity (BRS) and the SD of the normal-to-normal RR intervals (SDNN). A composite index of cardiac autonomic function was assessed by combining HR turbulence (TO and TS), BRS, and SDNN. Both TO and TS correlated moderately but significantly with BRS and SDNN (r = 0.26 to 0.44, p <0.001 for all correlations). On Cox's univariate regression analysis, the RRs for abnormal values of TO, TS, and the combination of abnormal TO and TS were 1.86 (95% confidence interval [CI] 0.96 to 3.61, p = 0.065), 4.08 (95% CI 2.11 to 7.89, p <0.0001), and 6.87 (95% CI 3.06 to 15.45, p <0.0001), respectively. The composite autonomic index (combined TO, TS, BRS, and SDNN) was the strongest risk predictor: for all 4 abnormal factors, RR 16.79 (95% CI 6.01 to 46.89, p <0.0001). On multivariate analysis, abnormal TO and TS, and left ventricular ejection fraction remained as independent predictors: RRs 4.07 (95% CI 1.70 to 9.77, p = 0.0017) and 3.53 (95% CI 1.76 to 7.06, p = 0.0004), respectively. In a separate model, the composite autonomic index was the strongest multivariate risk predictor: RR 8.67 (95% CI 2.72 to 7.65, p = 0.0003) for all abnormal factors, and adjusted for left ventricular ejection fraction. Thus, this study confirms the independent value of HR turbulence in predicting fatal cardiac arrest and nonfatal cardiac arrest in a low-risk post-acute myocardial infarction population. By combining HR turbulence, BRS, and SDNN, a comprehensive assessment of cardiac autonomic reflexes and modulation can be obtained.

Comparison between ventricular gradient and a new descriptor of the wavefront direction of ventricular activation and recovery.

BACKGROUND: Total R T cosine (TCRT) is a new descriptor of repolarization heterogeneity that quantifies the deviation between the directions of ventricular depolarization and repolarization. It revives the old concept of ventricular gradient (VG). HYPOTHESIS: Our goal was to examine whether TCRT and VG contain nonredundant information by comparing their reaction to autonomic tests, namely, postural changes and Valsalva maneuver. METHODS: Digital 12-lead electrocardiograms were recorded in 16 patients with cardiovascular syndrome X (SX, chest pain, exercise-induced ST-depression, normal coronary arteries, 3 men, age 60 +/- 9 years) and 40 healthy volunteers (31 men, age 33 +/- 7 years) during postural changes and Valsalva maneuver. The angle (VGA) [degrees] and magnitude (VGM) [ms.mV] of VG in reconstructed XYZ leads and TCRT (average cosine of the angles between the QRS and T vectors in mathematically reconstructed three-dimensional space) were calculated. RESULTS: (mean +/- standard of the mean): In healthy subjects, VGM and TCRT decreased, whereas VGA increased in the sitting and standing compared with supine position (TCRT: 0.61 +/- 0.05,0.47 +/- 0.06,0.29 +/- 0.08, supine, sitting, and standing, p < 0.05) and during phase II Valsalva (TCRT: 0.47 +/- 0.06 vs. 0.61 +/- 0.05, p < 0.01 in supine, 0.24 +/- 0.08 vs. 0.37 +/- 0.07, p < 0.01 in standing). In patients with SX, VGM decreased in the standing position, VGA did not change significantly, while TCRT decreased only in patients without T-wave abnormalities (n = 9) (TCRT in standing and supine: 0.55 +/- 0.09 vs. 0.68 +/- 0.08, p < 0.05). VG(M) increased during Valsalva in patients with SX. Total R T cosine correlated strongly with VGA (r = -0.84, p < 0.00001) and, unlike VGM, did not correlate with heart rate. CONCLUSIONS: Ventricular gradient and TCRT contain nonredundant information. In healthy subjects, they react sensitively to autonomic provocation. In patients with SX, their reaction is attenuated, which suggests disturbance of the autonomic control of repolarization.

A rare complication following radiofrequency ablation.

Atrial-oesophageal fistula (AOF) formation is a rare but often fatal complication post radio frequency ablation (RFA). Mortality ranges from 67% to 100%, with a rapid progression from symptom onset to death. We report a case of a healthy man in his early 40s who presented with a Glasgow Coma Scale  of 5/15, clinical evidence of sepsis and Streptococcus viridans bacteraemia, 14 days following uncomplicated RFA for atrial fibrillation. Establishing a diagnosis of AOF can be difficult, as patients may have bacteraemia, but are consequently misdiagnosed with infective endocarditis, as in this case. One should have a high-index of suspicion for AOF in patients presenting with the aforementioned constellation of symptoms following ablation. There are no established predictors of mortality, but prompt detection, emergent operative intervention and prolonged antibiotic therapy are vital for survival.

Diagnostic dilemmas in cardiology.

A 29-year-old pregnant woman presented in accident and emergency with severe acute left ventricular failure requiring admission to the intensive care unit. A nasal swab was found to be positive for H1N1 making peripartum and viral cardiomyopathies, the most likely differential diagnoses. CT coronary angiography and subsequent invasive angiography revealed an anomalous coronary system thus making ischaemic cardiomyopathy also a possibility. Cardiac MRI played a vital role in identifying the underlying cause, which in this case was that of H1N1 influenza cardiomyopathy. Correct diagnosis in such patients is paramount as this impinges on patients' overall prognosis. In this case aggressive initial therapy including inotropic support and invasive ventilation followed by standard antifailure treatment with ß-blockers and angiotensin-converting enzyme inhibitors led to restoration of the patient's left ventricular function and an associated marked improvement in symptoms.

Transcatheter aortic valve implantation for stenosed and regurgitant aortic valve bioprostheses CoreValve for failed bioprosthetic aortic valve replacements.

Transcatheter aortic valve implantation is increasingly being used to treat severe aortic stenosis in patients with high operative risk. In an aging population the incidence of aortic stenosis is rising, and increasing numbers of elderly patients are undergoing aortic valve replacement with bioprosthetic valves. Therefore, there is a corresponding increase in prosthetic degeneration. This presents cardiologists with a cohort of patients for whom the risk of re-do aortic valve surgery is prohibitive. We present the first series of such patients with degenerative bioprosthetic stenosis or regurgitation successfully treated with CoreValve (Medtronic, Luxembourg) implantation.

Primary percutaneous coronary intervention in saphenous vein grafts: a visualization strategy to improve outcome with new uses for the aspiration catheter.

Primary percutaneous coronary intervention (PCI) of saphenous vein grafts (SVG) is often a high-risk procedure associated with poor short- and long-term outcomes. Venous grafts frequently supply a clinically important myocardial territory. These vessels, however, combine the problems of a less predictable course and run-off as compared to native vessels with the presence of severe degenerative atherosclerosis. These factors amplify the risk due to an increased chance of distal embolization and no-reflow. We present three different situations during primary PCI in SVGs where a thrombosuction catheter was utilized to visualize the problem and then apply therapeutic maneuvers that proved crucial in achieving a successful result.

Ventricular gradient as a risk factor in survivors of acute myocardial infarction.

The total cosine between R and T (TCRT) (angular difference between the spatial QRS and T wave loops) is a technical elaboration of the concept of ventricular gradient (VG), whose power as a risk stratifier in post-MI patients has already been demonstrated. Recently, it was reported that TCRT differed significantly between healthy men and women, which suggested that its predictive power might be gender dependent. The aim of the study was to investigate TCRT and its association with cardiac mortality in male and female survivors of acute MI. TCRT was measured from digital Frank orthogonal XYZ-lead ECGs recorded before hospital discharge in 681 survivors of acute MI (82% men, age: men 57.0 +/- 8.4 years, women 59.6 +/- 8.1 years, P = 0.002). During a follow-up censored at 5 years, cardiac mortality rates were 9.7% and 12.1% in men and women, respectively (P = 0.42). There were no significant difference in TCRT between men and women (-0.150 +/- 0.704 vs -0.070 +/- 0.731, P = 0.26). In univariate Cox regression analysis, TCRT < -0.88 was related to a 5-year cardiac mortality in men (relative risk [RR] 3.67, 95% confidence interval [CI] 2.13-6.34, P = 1.9 x 10(-6)), and women (RR 5.16, 95% CI 1.83-14.56, P = 0.0015). Depressed TCRT was strongly associated with increased long-term cardiac mortality in survivors of acute MI. Its predictive power did not differ significantly between the sexes. The role of TCRT as a risk-stratifier in post-MI patients deserves further prospective assessment in multivariate models with established risk factors.

Preoperative electrocardiographic risk assessment of atrial fibrillation after coronary artery bypass grafting.

INTRODUCTION: This study evaluated the role of surface ECG in assessment of risk of new-onset atrial fibrillation (AF) after coronary artery bypass grafting surgery (CABG). METHODS AND RESULTS: One hundred fifty-one patients (126 men and 25 women; age 65 +/- 10 years) without a history of AF undergoing primary elective and isolated CABG were studied. Standard 12-lead ECGs and P wave signal-averaged ECG (PSAE) were recorded 24 hours before CABG using a MAC VU ECG recorder. In addition to routine ECG measurements, two P wave (P wave complexity ratio [pCR]; P wave morphology dispersion [PMD]) and six T wave morphology descriptors (total cosine R to T [TCRT]; T wave morphology dispersion of ascending and descending part of the T wave [aTMD and dTMD], and others), and three PSAE indices (filtered P wave duration [PD]; root mean square voltage of terminal 20 msec of averaged P wave [RMS20]; and integral of P wave [Pi]) were investigated. During a mean hospital stay of 7.3 +/- 6.2 days after CABG, 40 (26%) patients developed AF (AF group) and 111 remained AF-free (no AF group). AF patients were older (69 +/- 9 years vs 64 +/- 10 years, P = 0.005). PD (135 +/- 9 msec vs 133 +/- 12 msec, P = NS) and RMS20 (4.5 +/- 1.7 microV vs 4.0 +/- 1.6 microV, P = NS) in AF were similar to that in no AF, whereas Pi was significantly increased in AF (757 +/- 230 microVmsec vs 659 +/- 206 microVmsec, P = 0.007). Both pCR (32 +/- 11 vs 27 +/- 10) and PMD (31.5 +/- 14.0 vs 26.4 +/- 12.3) were significantly greater in AF (P = 0.012 and 0.048, respectively). TCRT (0.028 +/- 0.596 vs 0.310 +/- 0.542, P = 0.009) and dTMD (0.63 +/- 0.03 vs 0.64 +/- 0.02, P = 0.004) were significantly reduced in AF compared with no AF. Measurements of aTMD and three other T wave descriptors were similar in AF and no AF. Significant variables by univariate analysis, including advanced age (P = 0.014), impaired left ventricular function (P = 0.02), greater Pi (P = 0.012), and lower TCRT (P = 0.007) or dTMD, were entered into multiple logistic regression models. Increased Pi (P = 0.038), reduced TCRT (P = 0.040), and lower dTMD (P = 0.014) predicted AF after CABG independently. In patients <70 years, a linear combination of increased pCR and lower TCRT separated AF and no AF with a sensitivity of 74% and specificity of 62% (P = 0.005). CONCLUSION: ECG assessment identifies patients vulnerable to AF after CABG. Combination of ECG parameters assessed preoperatively may play an important role in predicting new-onset AF after CABG.

QT-RR relationship in healthy subjects exhibits substantial intersubject variability and high intrasubject stability.

Recently, it was demonstrated that the QT-RR relationship pattern varies significantly among healthy individuals. We compared the intra- and interindividual variations of the QT-RR relationship. Twenty-four-hour 12-lead digital electrocardiograms (ECGs; SEER MC, GE Marquette; 10-s ECG recorded every 30 s) were obtained at baseline and after 24 h, 1 wk, and 1 mo in 75 healthy subjects (42 women, 33 men, age 27.9 +/- 9.6 vs. 26.8 +/- 7.5 yr, P = not significant). QT interval was measured automatically in each ECG by six different algorithms, and the mean of the six measurements was analyzed. In each recording of each individual, QT-RR relationship was assessed by 10 different regression models including linear (QT = beta + alpha x RR) and parabolic (QT = beta x RR(alpha)) models. Standard deviations (SDs) of regression parameters alpha and beta of consecutive recordings of each individual were compared with SD of the individual means. Intrasubject stability and interindividual variability were further tested by ANOVA. With all models, intraindividual SDs of the regression parameters were highly significantly smaller than SD of individual means (P < 10(-5)-10(-9)). The intrasubject stability was further confirmed by ANOVA (P < 10(-19)-10(-30)). The QT-RR relationship exhibits substantial intersubject variability as well as a high intrasubject stability. This has practical implications for a precise estimation of the heart rate-corrected QT interval in which optimized subject-specific rate correction formulas should be used.