Saturday, May 28, 2011
Wednesday, May 25, 2011
Published online before print May 23, 2011
The QT and Corrected QT Interval in Recovery After Exercise in Children
Wouter Rudolph Berger, Robert M. Gow, Suleman Kamberi, Michael Cheung, Katherine Rose Smith and Andrew Mark Davis
Background—Prolongation of the QT interval after exercise can be used to help diagnose Long QT syndrome, especially when the resting QT interval is borderline. The aim of this study was to determine the normal ranges for QT/QTc in the recovery phase after exercise in children.
Methods and Results—Ninety-four volunteer boys and girls aged 8 to less than 17 years, without any history of heart disease underwent exercise testing and had 12 lead ECGS performed in the supine position for 10 minutes of recovery. The QT was measured using a standardized tangent method with the baseline defined as the Q to Q line. The recovery QT was maximally short at 1 minute of recovery in 93/94 individuals, then lengthened and stabilized at 4 to 5 minutes recovery. The recovery QT lengthens as HR decreases in an approximately linear fashion with a mean increase of 15 milliseconds per 10 beat decrease in heart rate. The 98th percentiles for the QTc using the Bazett formula during minutes 4 to 6 in recovery were from 482 msec to 491 msec. There was excellent intra-observer and inter-observer reliability with intra-class correlation coefficients of 0.95 and 0.88 respectively.
Conclusions—There is substantial individual variability of the normal repolarization process in the post-exercise recovery period in children. The study provides a reference for normal responses for similar populations using a specific measurement protocol that can be easily applied.
Tuesday, May 24, 2011
Coffee Okay for Well-Managed Hypertensives
By Todd Neale, Staff Writer, MedPage Today
Published: May 23, 2011
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
In a meta-analysis of five trials, consuming 200 to 300 milligrams of caffeine -- the amount found in one-and-a-half to two cups of coffee -- produced a mean increase in blood pressure of 8.1/5.6 mm Hg, according to Esther Lopez-Garcia, PhD, of Autonoma University of Madrid.
The effect was observed within the first hour and sustained for up to three hours, she reported at the American Society of Hypertension meeting here.
Although meta-analyses of studies looking at the longer-term effects could not be conducted because of methodological differences, the bulk of the evidence pointed to a lack of an effect from coffee and caffeine intake on blood pressure and cardiovascular risk.
The association between coffee drinking and blood pressure has been well studied in normotensive individuals, with consistent findings of an acute increase in blood pressure after intake but no long-term risk of becoming hypertensive or having a cardiovascular event, according to Lopez-Garcia.
Some studies have even tied coffee drinking to a lower stroke risk, including a Swedish cohort study and an analysis of the Nurses' Health Study.
However, the relationship has not been studied as thoroughly in hypertensive individuals, in whom even a slight increase in blood pressure might be harmful.
In addition, Lopez-Garcia said that it is unknown whether coffee might reduce the effect of antihypertensive drug treatment and whether hypertensive individuals are able to develop a tolerance to caffeine like their normotensive counterparts.
Thus, she said, evidence is insufficient to guide medical advice regarding coffee and caffeine consumption in hypertensive individuals.
To explore the issue, Lopez-Garcia and her colleagues reviewed the literature and performed meta-analyses when possible.
In the meta-analysis of trials examining the acute effect of coffee and caffeine consumption, blood pressure was increased in the first three hours after intake, regardless of the duration of caffeine abstinence before the trial started and of the use of antihypertensive drugs.
Four other studies examined the longer-term effects of interventions involving coffee or caffeine intake. The two studies comparing coffee versus decaffeinated coffee found no longer-term effect on blood pressure up to eight weeks after the intervention.
Of two studies comparing coffee with a caffeine-free diet, however, one demonstrated a significant increase in systolic blood pressure in the coffee group (mean change 5.2 mm Hg). That came with an intervention consisting of drinking five cups of coffee a day.
There is not enough evidence to draw firm conclusions, Lopez-Garcia said, but the bulk of the evidence suggests that there is no longer-term effect on blood pressure from drinking coffee or caffeinated beverages.
A meta-analysis also was not possible for the five cohort studies -- with durations ranging from four to 25 years -- examining the relationship between habitual consumption of coffee and caffeinated beverages and cardiovascular risk.
Three studies found no association between habitual caffeine intake and risk of cardiovascular mortality.
Of two studies using stroke as an endpoint, one found a doubling in the risk (RR for the consumption of 20 ounces of coffee per day 2.1, 95% CI 1.2 to 3.7). The other failed to show a significant association.
Overall, the findings suggest that the relationship between coffee and caffeine consumption and blood pressure is similar in hypertensive and normotensive individuals, Lopez-Garcia said.
She said that one of the clinical implications of the findings is that the consumption of coffee or caffeinated beverages may alter blood pressure measurements in routine check-ups.
The findings also show that in hypertensive patients with well-controlled blood pressure, it may be safe to consume coffee, she added, but "for patients with uncontrolled blood pressure, moderation in coffee consumption is suggested."
The study was funded in part by an FIS research grant. Lopez-Garcia was supported by a Ramón y Cajal contract, and one of her co-authors was supported by a MAEC-AECID fellowship.
Lopez-Garcia reported that she had no conflicts of interest.
Friday, May 20, 2011
EuroPCR: Novel Metal Stent Does Disappearing Act
By Crystal Phend, Senior Staff Writer, MedPage TodayPublished: May 19, 2011
Reviewed by Zalman S. Agus, MD; Emeritus Professor University of Pennsylvania School of Medicine andDorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
PARIS -- A novel drug-eluting stent may do away with the permanent metal jacket, according to early results with a bioabsorbable metal scaffold.The paclitaxel-eluting magnesium alloy stent degrades away after about nine months to a soft hydroxyapatite absorbed by the body, Michael Haude, MD, of Städtische Kliniken Neuss Lukaskrankenhaus in Neuss, Germany, and colleagues reported.First-in-man results suggested a 9.1% target lesion failure rate -- two revascularizations -- and 0.68 mm late lumen loss at six months in a small, 22-patient study Haude presented here at the European Society of Cardiology's EuroPCR meeting."We feel that we are on the right direction," Haude told MedPage Today at a press conference.
Bioabsorbable polymer scaffold stents have been developed as well, but a metal backbone holds clear advantages for conforming to the vessel, Haude explained.
"It is really adapting to the vessel size, and, of course, you can overstress it, you can dilate it, which is not to that extent possible with most of the polymers that are on the market," he said at the session.
While the novel technology still needs to prove itself against conventional drug-eluting stents, there would likely be advantages for treating younger patients in earlier stages of coronary artery disease, he suggested.
These patients with decades of life expectancy "obviously don't want to have a permanent scaffold stent within their arteries for the rest of their life," Haude told attendees.
The researchers tweaked the design of the stent, adding a bioabsorbable paclitaxel-eluting polymer coating and extending the scaffold degradation time, then tested it in 46 patients with de novo coronary artery stenosis in the BIOSOLVE-I study.
The 22 patient cohort with clinical follow-up at six months showed 100% procedural and technical successes. No deaths, heart attacks, or scaffold thrombosis were seen, though two patients required clinically driven target lesion revascularization by six months due to angina.
The in-scaffold late lumen loss was 0.68 mm at six months, which was a 37% improvement over results with the prior bare metal version of the stent. The 9.1% target lesion revascularization rate was a 62% improvement over results with the prior version.
The second cohort, which will have a 12-month follow-up, should provide additional information on long-term safety and efficacy of the new scaffold, Haude noted.
By comparison, first-in-man trials with conventional stents had reported late lumen loss of 0.10 with the Xience V stent, 0.09 mm with Cypher, and 0.12 mm with Endeavor, as Martial Hamon, MD, of the University Hospital of Caen in Normandy, France, noted in a separate presentation at the session.
Also for comparison purposes, at six months the late lumen loss was 0.44 mm and the restenosis rate was 11.5% for the first-in-man trial of an everolimus-eluting polymer bioabsorbable coronary stent.
The study was sponsored by Biotronik.
Haude reported research contracts with Biotronik, OrbusNeich, Cordis, Medtronic, Cardiac Dimensions, and Volcano as well as consulting for Biotronik and OrbusNeich.
Hamon reported consulting for Biotronik.
Primary source: European Association of Percutaneous Cardiovascular InterventionsSource reference:Haude M, et al "BIOSOLVE-I safety and clinical performance of the first drug-eluting absorbable metal scaffold" EuroPCR 2011.
Wednesday, May 18, 2011
The Journal of Thoracic and Cardiovascular Surgery Volume 141, Issue 6, June 2011, Pages 1346-1354
Congenital heart disease
Primary sutureless repair for “simple” total anomalous pulmonary venous connection: Midterm results in a single institution
Bobby Yanagawa MD, PhDa, Abdullah A. Alghamdi MD, MSca, Andreea Dragulescu MDb, Nicola Viola MDa, Osman O. Al-Radi MDa, Luc L. Mertens MD, PhDb, John G. Coles MDa, Christopher A. Caldarone MDa and Glen S. Van Arsdell MDa, ,
We have previously reported the use of an atriopericardial or “sutureless” repair for surgical management of postoperative pulmonary vein stenosis. The potential of avoiding geometric distortion of pulmonary venous suture lines and preventing post-repair pulmonary vein stenosis encouraged us to extend the use of this technique for primary “simple” total anomalous pulmonary venous connection repair.
Between January 1997 and July 2009, 57 consecutive patients (median age, 15 days; median weight, 3.4 kg) underwent sutureless or conventional total anomalous pulmonary venous connection repair.
Types of total anomalous pulmonary venous connection included supracardiac in 31 patients (54%), cardiac in 15 patients (26%), and infracardiac in 11 patients (19%). Median follow-up time was 2.9 years. Preoperative mean pulmonary vein score, a composite measure of stenosis in all 4 pulmonary veins, was 0.3/0–12, and vertical vein obstruction was found in 35 patients (61.4%). A primary sutureless repair was carried out in 21 patients (36.8%; supracardiac, n = 12; cardiac, n = 4; infracardiac, n = 5). The sutureless repair group had proportionally greater high-risk infracardiac total anomalous pulmonary venous connection (24% vs 16%, P = .05). Primary outcomes of death or reoperation for pulmonary vein stenosis and postoperative pulmonary vein scores (0.2 ± 0.7 vs 0.7 ± 1.7, P = .26) were not different between the techniques.
The sutureless repair group had proportionally more infracardiac total anomalous pulmonary venous connection and a higher rate of decline in postoperative right ventricular systolic pressure. Despite increased preoperative risk, no difference was observed in primary outcomes of death and reoperation in the conventional repair group.
Referenced here, more to highlight the methodology of the adult study and for actual reports of measurement dose, etc. This adult study compares right and left radial access. Radiation exposures were similar between right and left radial approached. Slightly increased exposure to the wrist in right radial approach compared to left radial approach.
Operator Radiation Exposure During Percutaneous Coronary Procedures Through the Left or Right Radial Approach
The TALENT Dosimetric Substudy
- Alessandro Sciahbasi, MD at al.
Background—Transradial percutaneous coronary procedures may be effectively performed through the right radial approach (RRA) or the left radial approach (LRA), but data on radiation dose absorbed by operators comparing the two approaches are lacking. The aim of the present study was to evaluate radiation dose absorbed by operators during coronary procedures through the RRA and LRA.
Methods and Results—Three operators were equipped with 5 different dosimeters (left wrist, shoulder, thorax outside the lead apron, thorax under the lead apron, and thyroid) during RRA or LRA for coronary procedures. Each month, the dosimeters were analyzed to determine the radiation dose absorbed. From February to December 2009, 390 patients were randomly assigned to the RRA (185 patients; age, 66±11 years) or the LRA (185 patients; age, 66±11 years). There were no significant differences in fluoroscopy time (for RRA, 369 seconds; interquartile range, 134 to 857 seconds; for LRA, 362 seconds; interquartile range, 142 to 885 seconds; P=0.58) between the 2 groups. There were no significant differences in monthly radiation dose at the thorax (0.85±0.46 mSv for RRA and 1.12±0.78 mSv for LRA, P=0.33), at the thyroid (0.36±0.2 mSv for RRA and 0.34±0.3 mSv for LRA, P=0.87), and at the shoulder (0.73±0.44 mSv for RRA and 0.94±0.42 mSv for LRA, P=0.27). The dose at the wrist was significantly higher for the RRA (2.44±1.12 mSv) compared with the LRA (1±0.8 mSv, P=0.002). In both radial approaches, the thoracic radiation dose under the lead apron was undetectable.
Conclusions—Compared with RRA, LRA for coronary procedures is associated with similar radiation dose for operators at the body, shoulder, or thyroid level, with a possible significant advantage at the wrist. The cumulative radiation dose for both approaches is well under to the annual dose-equivalent limit.
Tuesday, May 3, 2011
Circulation: Cardiovascular Imaging
X-ray Magnetic Resonance Fusion to Internal Markers and Utility in Congenital Heart Disease Catheterization
Yoav Dori1*, et al.
The Children's Hospital of Philadelphia, Philadelphia, PA & Siemens Healthcare, Malvern, PA
Corresponding author; email: email@example.com
Background—X-ray magnetic resonance fusion (XMRF) allows for utilization of 3D data during cardiac catheterization. However, to date, technical requirements have limited the use of this modality in clinical practice. Here we report on a new internal marker XMRF method that we have developed and describe how we used XMRF during cardiac catheterization in congenital heart disease.
Methods and Results—XMRF was performed in a phantom and in 23 patients presenting for cardiac catheterization who also needed cardiac MRI for clinical reasons. The registration process was performed in less than 5 minutes per patient with minimal radiation (0.004 - 0.024 mSv) and without contrast. Registration error was calculated in a phantom and in 8 patients using the maximum distance between angiographic and 3D model boundaries. In the phantom the measured error in the AP projection had a mean of 1.15 mm (standard deviation 0.73). The measured error in patients had a median of 2.15 mm (IQR 1.65 - 2.56 mm). Internal markers included bones, airway, image artifact, calcifications, and the heart and vessel borders. The MRI data was used for road mapping in 17/23 (74%) cases and camera angle selection in 11/23 (48%) cases.
Conclusions—Internal markers based registration can be performed quickly, with minimal radiation, without the need for contrast, and with clinically acceptable accuracy using commercially available software. We have also demonstrated several potential uses for XMRF in routine clinical practice. This modality has the potential to reduce radiation exposure and improve catheterization outcomes.
Two video links:
Video showing MRI fusion with fluoro guiding cath procedure: