Thursday, July 29, 2010

Laryngopharyneal Dysfunction after Norwood

J Thorac Cardiovasc Surg. 2005 Nov;130(5):1293-301. Epub 2005 Oct 13.
Laryngopharyngeal dysfunction after the Norwood procedure.
Skinner ML, Halstead LA, Rubinstein CS, Atz AM, Andrews D, Bradley SM.
Evelyn Trammell Institute of Voice and Swallowing, Department of Otolaryngology-Head and Neck Surgery, Charleston, SC, USA.


OBJECTIVE: We sought to evaluate the incidence and significance of recurrent laryngeal nerve and swallowing dysfunction after a Norwood procedure compared with that after biventricular aortic arch reconstruction.

METHODS: From April 2003 through December 2004, 36 neonates underwent a Norwood procedure; 33 of 36 had postoperative fiberoptic laryngoscopy and modified barium swallow. Study results were used to guide the transition from nasogastric tube to oral feeding and placement of gastrostomy tubes. During the same time period, 18 neonates underwent aortic arch reconstruction as part of a biventricular repair.

RESULTS: After a Norwood procedure, laryngoscopy showed left true vocal fold (cord) paralysis in 3 (9%) of 33 patients. The results of a modified barium swallow were abnormal in 16 (48%) of 33 patients, with aspiration in 8 (24%) of 33 patients. Of the 3 patients with vocal fold paralysis, 2 had a normal modified barium swallow result, and 1 had aspiration. Gastrostomy tubes were placed in 6 (18%) of 33 patients, all with an abnormal modified barium swallow result. Hospital stay was longer in patients with an abnormal modified barium swallow result: 34 +/- 13 versus 22 +/- 7 days (P < .01).

After biventricular repair with aortic arch reconstruction, left true vocal fold paralysis occurred in 4 (25%) of 16 patients; results of a modified barium swallow were abnormal in 10 (59%) of 17 patients, with aspiration in 6 (35%) of 17 patients (all nonsignificant vs patients undergoing the Norwood procedure). Follow-up laryngoscopy in 4 patients with vocal fold paralysis showed no change in 3 of 4 patients and improvement in 1 patient. Follow-up modified barium swallow showed resolution of aspiration in 11 (85%) of 13 patients.

Hospital survival was 32 (89%) of 36 patients for the Norwood procedure and 18 (100%) of 18 patients for biventricular repair. There has been 1 sudden death before second-stage palliation.

CONCLUSIONS: After a Norwood procedure, swallowing dysfunction occurs in 48% of patients, with aspiration in 24%, and results in increased length of hospital stay. Left recurrent laryngeal nerve injury, seen in 9% of patients, is an uncommon cause of swallowing dysfunction. Postoperative aspiration generally resolves over time, whereas vocal fold paralysis does not. Systematic evaluation of swallowing function allows appropriate tailoring of feeding regimens and might contribute to decreased hospital and interstage mortality.

PMID: 16256781 [PubMed - indexed for MEDLINE]

Inhaled nitric oxide after Glenn

J Thorac Cardiovasc Surg. 2005 Jan;129(1):217-9.
Inhaled nitric oxide does not improve systemic oxygenation after bidirectional superior cavopulmonary anastomosis.
Adatia I, Atz AM, Wessel DL.
Department of Cardiology, Children's Hospital, Harvard Medical School, Boston, MA, USA.
PMID: 15632849 [PubMed - indexed for MEDLINE]

Sunday, July 25, 2010

Surgery: Pulmonary atresia - VSD, MAPCAs, Unifocalization

Circulation. 2000 Apr 18;101(15):1826-32.
Early and intermediate outcomes after repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 85 patients.
Reddy VM, McElhinney DB, Amin Z, Moore P, Parry AJ, Teitel DF, Hanley FL.
Divisions of Cardiothoracic Surgery, University of California, San Francisco 94143-0118, USA.

BACKGROUND: Pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collaterals (MAPCAs) is a complex lesion with marked heterogeneity of pulmonary blood supply. Traditional management has involved staged unifocalization of pulmonary blood supply. Our approach has been to perform early 1-stage complete unifocalization in almost all patients.

METHODS AND RESULTS: Since 1992, 85 patients with pulmonary atresia, VSD, and MAPCAs have undergone unifocalization (median age, 7 months). Complete 1-stage unifocalization and intracardiac repair were performed through a midline approach in 56 patients, whereas 23 underwent unifocalization in a single stage with the VSD left open, and 6 underwent staged unifocalization through sequential thoracotomies. There were 9 early deaths. During follow-up (1 to 69 months), there were 7 late deaths. Actuarial survival was 80% at 3 years. Among early survivors, actuarial survival with complete repair was 88% at 2 years. Reintervention on the neo-pulmonary arteries was performed in 24 patients.

CONCLUSIONS: Early 1-stage complete unifocalization can be performed in >90% of patients with pulmonary atresia and MAPCAs, even those with absent true pulmonary arteries, and yields good functional results. Complete repair during the same operation is achieved in two thirds of patients. There remains room for improvement; actuarial survival 3 years after surgery is 80%, and there is a significant rate of reintervention. These results must be appreciated within the context of the natural history of this lesion: 65% of patients survive to 1 year of age and slightly >50% survive to 2 years even with surgical intervention.

MAPCAs arrangement in 11 patients with PA-VSD reported in JTCVS 1997 paper from Quebec:
J Thorac Cardiovasc Surg 1997;114:727-737. One-satge midline unifocalization and complete repair in infancy versus multiple-stage unifocalization followed by repair for complex heart disease with major aorto-pulmonary collaterals. Christo I. Tchervenkov et al.

Group I (pt #1-6) had multi-stage repair:
Group II (pt #7-11) had single-stage repair:
Also see other postings on this subject:
Pre-op evaluation of PAs and MAPCAs
Surgery Algorithms for PA-VSD

Friday, July 23, 2010

NIRS - Normal values in newborn

Abstract presented at AAP conference 2009 (Washington, DC)
Cerebral and Somatic NIRS Oximetry in Normal Newborn.
Nicole P. Bernal, George M. Hoffman, Nancy S. Ghanayem, Marjorie K. Arca.
(Editorial note: Somatic = renal, in this abstract)

Purpose: Establishing normal value for newborn during rest and feeding.

44 term newborns
Probes in forehead and right flank (T12-L2) over right kidney
Reading collected continuously for 2-8 hrs (1-3 feeds)
Data captured at 0.1 Hz (i.e. every 10 sec) and averaged to 1 min.
Somatic - Cerebral difference - as an index of relative regional oxygen extraction.

Time series fixed effects & Mixed model regression techniques (Stata 10.1) for the following -
Difference over time
Difference between babies
Difference between states (resting vs. feeding)


Age 44 +/- 28 hrs
Wt 3.2 +/- 0.48 kg
Mean duration of observation 417 /- 255 min

At rest:
Average Cerebral rSO2 = 77.9
Overall +/- 8.5
Within babies +/- 6.1 (16-95)
Between babies +/- 6.3 (64-87)

Average Renal rSO2 = 86.8
Overall +/- 8.1
Within babies +/- 5.9 (40-95)
Between babies +/- 5.8 (74-94)

Average Diff. between Renal to Cerebral rSO2 indices = 8.9%
Overall +/- 9.4
Within babies +/- 8.0
Between babies +/- 5.2

During feeding:
Cerebral rSO2 index decreased (78.6 +/- 8.4 >>> 78.0 +/- 9.0; p 0.023)
Renal rSO2 index did not change (87.0 +/- 8.1 >>> 87.3 +/- 8.0; p=0.31)
Diff. between Renal to Cerebral rSO2 indices increased (8.5 +/- 9.5 >>> 9.2 +/- 9.1; p=0.014)

Over the first 120 hrs after birth, (Figure 2)
Average Cerebral rSO2 index slightly decreased (p <>
Average Renal rSO2 index was unchanged.

Cath: Incidence of renal function abn. after catheterization

From Nationwide Children's Hosp. Presented at PICS 2010 Chicago.
Cath Cardiovasc Interv 2010 July; 76(1):S9

Intro: Recommendations for maximum dose is outdated and not made for current contrast agents and current procedure lengths.

Methods: 2006-9, 135 procedures requiring ICU care after cath.
Study population: 60 procedures where non-ionic contrast (Optiray) was used, pre- and post-procedural data were available, etc.
2/3rd of patients had renal parameters measured at least 3 times for 72 hrs.
Age: 1 day - 18 yrs. Median = 6 months.
95% were < 1 year.

Contrast used: 0.6 - 6.1 ml/kg (median 3 ml/kg) Contrast used per hour of procedure: 0.1 - 7.4 ml/kg/hr (median 1.7 ml/kg/hr) 3 pts. received large amount of contrast (> 10 ml/kg). But, this was administered over longer procedures (<4.5 ml/kg/hr).

No change in median values of Creatinine or Creatinine clearance between pre- and post-procedure values.
6 pts(10%) had increase in creatinine > 150% &/or decrease in Creatinine clearance >25%.
1 pt (1.7%) had increase in creatinine >200% and decrease in Creatinine clearance >50%.
All these pts. rec'd < 6 ml/kg and < 4.1 ml/kg/hr.

Risk factors were (i) pre-procedural renal impairment (n=3) & (ii) procedure-related hemodynamic instability during the procedure.
No one needed RRT.

Conclusion: Large amounts of contrast (>10 ml/kg) is tolerated provided it is administered over a longer period. Pre-procedural renal impairment and procedure-related hemodynamic instability are risk factor for development of renal compromise (Increase in creatinine and Decrease creatinine clearance).

Cath: Pressure wire

The use of pressure wire to evaluate congenital and structural heart disease.
Kempton, TM, et al. Nationwide Children's Hospital, Columbus, OH.
Presented at 2010 PICS meeting, Chicago. Cath Cardiovasc Interv 2010 July;76(1):S4.

Intro: Pressure wire is useful when catheter can not be used due to damping effect, catheter entrapment (e.g. via stent) and hemodynamic instability (e.g. stenosed coarctation, PDA, retrograde arch, etc).

Equipment: 0.014" pressure wire.

Used for the following circumstances:
Hybrid cases - retrograde arch, PDA stent, PA bands, atrial septum (in 30% of procedures)
Vessels jailed by stents (7% of procedures)
Branch PA stenosis (41% of procedures)
Pulmonary vein stenosis (10%)
AS (sub, supra & valvar) (10%)
Prosthetic valve (3%)
MAPCAs (12%)
Others (19%)

Intended information was obtained in all cases. No adverse reactions.
More than one wire was used in 12% due to kinking of wire, baseline shift with inability to calibrate and/or wire dysfunction.

Complements the interventional armamentarium.
Safe and facilitates measurements when catheter use is inappropriate or contraindicated.
Pressure wire is very sensitive to small kinks.
Operator should be aware of need for frequent calibration due to baseline shift.

Wednesday, July 21, 2010

RF Perforation and balloon valvuloplasty in PA-VSD as palliation

Catheter Cardiovasc Interv 2007;69:1015-20
Walsh,M. et al. (Toronto)

A report of 8 cases (5 newborns) between 2000-2006.
RF was successful in 6 of 8 babies.
RF perforation was to be the first of 2 interventions. Second being surgical repair.
Procedure: 4 or 5 Fr sheath. JR 2 or 2.5 catheter placed perpendicular to pulmonary valve plane (LAO, cranial 10 deg & Straight lateral).
RF wire: First 3 cases - 0.018 wire (PA 120, Opsyka), last 5 (0.024 Baylis wire)
Energy applied: 3-10 W x 2-5 sec.
Once through, RF wire is exchanged to 0.038 Baylis coaxial catheter, 0.014 Wisdom coronary wire was placed.
Balloons: 2.5 - 3.5 coronary balloons. Then, upto 5 or 6 mm coronary balloons (20% more than diameter of RVOT)
RVgram...further balloon or stent performed depending on result. Stent placed in 1.
Complication: Inadvertent RVOT perforation (4 out of 8)!

Other references:
1. Kuhn MA et al. Valve perforation and balloon pulmonary valvuloplasty in an infant with TOF-PA. Catheter Cardiovasc Diagn 1997;40:403-6.
2. Housdorf, G. et al. RF-assisted "reconstruction of the RVOT in muscular PA-VSD. Br Heart J 1993;69:343-6.
3. Hausdorf, G. et al. Catheter creation of an open outflow tract in previously atretic RVOT associated with VSD. Am J Cardiol 1993;72:354-6.
4. Pagani FD, Cheatham JP, Beekman RH III, et al. Management strategy of TOF-PA and dimunitive pulmonary arteries. JTCVS 1995;110:1521-32.
5. Kreutzer J, Perry SB, Jonas RA, et al. TOF with dimunitive pulmonary arteries: Preoperative pulmonary valve dilation and transcatheter rehabilitation of pulmonary arteries. JACC 1996;27:1741-7.

Sunday, July 11, 2010

Dilated Cardiomyopathy - Treatment and Outcome

The impact of changing medical treatment on transplant-free survival in pediatric dilated cardiomyopathy. Paul F Kantor, Jonathan R. Abraham, Anne I. Dipchand, Lee N. Benson, Andrew N. Redington. JACC 2010;55:1377-84.

Single institution. Retrospective review of all patients over 30 years (1976-2005).
n-189, 44 died. 24 had transplant. 10 were lost to follow up. So, the study cohort n=111.
2-yr & 5-yr transplant-free survival = 63.6% and 56.3% respectively.

5-yr survival:
Digoxin only - 67.5%
Digoxin & ACEi - 57.2%
ACEi & BB - 58.5%

Multivariate analysis:
Low LVEF at presentation is associated with increased risk of death or transplantation.
End point was not influenced by time era or treatment strategy.

Saturday, July 10, 2010

Natural History of Endocarditis Vegetation

1) Natural history of vegetations during successful medical treatment of endocarditis.
Cedric Vuille, Mark Nidorf, Arthur Weyman and Michael Picard.
AHJ 1994;128:1200-9

41 vegetations in 32 patiens were followed.
At the end of initial treatment,
Resolution: 29 vegetations (70%) were still present.
Size: No change in size in 59%
Echogenicity: Vegetations appeared denser in 52% of them.
Morphologic changes were not associated with outcome.
Presence of severe valvar regurgitation was associated with late valve replacement.
Persistence of vegetation is common after successful treatment and is not independently associated with late complications.

2) Natural history of tricuspid valve endocarditis: A two dimensional echocardiographic study.
Leonard ginzton, Robert Siegel & Michael Criley
AJC 1982;49:1853-9.

Very old study, comparing M-mode and 2-D echo for tricuspid valve IE.
n=16 patients.
(5 of them needed surgery or died)
Change in vegetation size from 8 patients is depicted in this figure.
Note: from only 8/16 pts. Surgical patients are inlcuded!!! What does that mean...did the surgeon not remove them?!

Warfarin - Genotyping

Warfarin genotyping reduces hospitalization rates. Results from MM-WES (Medco-Mayo Warfarin Effectiveness Study).
Robert S. Epstein, et al. JACC 2010;55(25):2804-12.
Editorial comments

Two genes have been shown in past decade to influence warfarin dosing.
One gene, CYP2C9 determines the activity of hepatic isoenzyme cytochrome P450 2C9 that plays a role in converting S-war-farin to its inactive form.
Second gene, VKORC1 - determines the activity of Vit K epoxide reductase that produces the active form of Vit K that is necessary for clotting.

CYP 2C9 & NKORC1 polymorphisms account for > 1/3rd of variations associated with variations in warfarin dosage. Warfarin sensitivity genotyping involves a test that simultaneously tests for allelic variation in both genes.

Genetic testing is not widely adopted due to lack of studies demonstrating the utility of these tests. This is the first national study on this.

TGA - Outcome after ASO for TGA in adults

Cardiac outcomes in young adult survivors of the arterial switch operation for transposition of the great arteries.
Daniel Tobler, William G. Williams, Anusha Jegatheeswaran, et al.
JACC 2010;56(1):58-64.

132 infants discharges from Toronto before 1991.
97% survival at 20 yrs.
65 were followed in Toronto are the study population.
11 pts (17%) had at least one clinically significant lesion (Ventricular dysfunction, valvular dysfunction or arrhythmia)
Residual lesions are more common in patients who needed cath interventions during childhood (Odds ratio 10.7).

5 pts (8%) had arrhythmia.
7 (11%) needed reintervention (5 reops & 2 Pacemaker placements)
No intervention was necessary for AR or Aortic root dilatation.
Exercise capacity was reduced in 82% of survivors.

MRI: Early detection of Doxorubincin-induced cardiomyopathy

Early Detection of Doxorubicin Cardiotoxicity Using Gadolinium EnhancedCardiovascular Magnetic Resonance ImagingJames C. Lightfoot, Ralph B. D'Agostino, Jr, Craig A. Hamilton, JenniferJordan, Frank M. Torti, Nancy D. Kock, James Jordan, Susan Workman, and W.Gregory HundleyCirc Cardiovasc Imaging published 9 July 2010,10.1161/CIRCIMAGING.109.918540

Monday, July 5, 2010

Exercise induced Troponin increase - Review

JACC 2010;56:169-176

Review of increase in Troponin increase after strenuous physical exercise. Mechanisms and implications. Worth reading.

Wearable Cardioverter-Defibrillator

JACC 2010;56:194-203

JACC 2010;56:204-205

Just a novel idea. Defibrillator vest used in adults. Made by ZOLL. Approved by FDA in 2002. Interesting read. Something to consider in some pediatric patients.