Daniela Lax

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Journals/Publications

• Phillips, E., Shehab, Z. M., & Lax, D. (2017). Lemiere syndrome.. Southwest Journal of Pulmonary and Critical Care.
• Colombo, J. N., Seckeler, M. D., Barber, B. J., Krupinski, E. A., Weinstein, R. S., Sisk, D., & Lax, D. (2016). Application and Utility of iPads in Pediatric Tele-echocardiography. Telemedicine journal and e-health : the official journal of the American Telemedicine Association, 22(5), 429-33.
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  Telemedicine is used with increasing frequency to improve patient care in remote areas. The interpretation of medical imaging on iPad(®) (Apple, Cupertino, CA) tablets has been reported to be accurate. There are no studies on the use of iPads for interpretation of pediatric echocardiograms. We compared the quality of echo images, diagnostic accuracy, and review time using three different modalities: remote access on an iPad Air (iPad), remote access via a computer (Remote), and direct access on a computer linked through Ethernet to the server, the "gold standard" (Direct).
• Rischard, F. F., Vanderpool, R., Jenkins, I., Daiabih, M., Colombo, J., Lax, D., & Seckeler, M. M. (2015). Selective pulmonary vasodilation improves ventriculo-vascular coupling and gas exchange in a patient with unrepaired single ventricle physiology.. Pulmonary Circulation, 5(2), 407-411.
• Haley, J. E., Klewer, S. E., Barber, B. J., Meaney, F. J., Donnerstein, R. L., Weinstein, R. S., Krupinski, E., Warda, G., Lopez, A. M., & Lax, D. (2012). Remote diagnosis of congenital heart disease in southern Arizona: comparison between tele-echocardiography and videotapes. Telemedicine journal and e-health : the official journal of the American Telemedicine Association, 18(10), 736-42.
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  We report our experience with tele-echocardiography and echocardiograms recorded digitally or on videotape (recorded-echos) at The University of Arizona from August 2006 to December 2010 and compare their quality and diagnostic accuracy.
• Ihnat, C. L., Zimmerman, H., Copeland, J. G., Meaney, F. J., Sobonya, R. E., Larsen, B. T., Blair, B., Lax, D., & Barber, B. J. (2011). Left ventricular assist device support as a bridge to recovery in young children. Congenital heart disease, 6(3), 234-40.
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  Left ventricular assist device (LVAD) experience and follow-up data in children are limited. We report the deployment and successful weaning from LVAD in young children with severe heart failure (HF).
• Lax, D., Bhatt, R. D., Klewer, S. E., & Sorrell, V. L. (2010). Are all ventricular septal defects created equal?. Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 23(7), 791.e5-7.
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  The authors report the occurrence of infective endocarditis in a 32-year-old man with a ventricular septal defect and a left ventricular-to-right-atrial shunt who adhered to the revised 2007 American Heart Association guidelines for infective endocarditis. The patient had received antibiotic prophylaxis prior to multiple previous dental procedures. At a recent dental evaluation for fillings, he was informed that he no longer needed prophylaxis. Fatigue and fevers developed 1 week later, and he was treated with an oral course of ciprofloxacin. The symptoms recurred, and blood cultures grew Streptococcus viridans. A 7-mm vegetative mass was seen on the septal leaflet of the tricuspid valve during transesophageal echocardiography. This report raises the concern that patients with ventricular septal defects and left ventricular-to-right-atrial shunts are at higher risk for endocarditis and may require antibiotic prophylaxis.
• Cragun, D. T., Lax, D., & Butman, S. M. (2005). Look before you close: atrial septal defect with undiagnosed partial anomalous pulmonary venous return. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, 66(3), 432-5.
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  The growing and continued success of percutaneous closure of atrial defects is related to its high benefit-to-risk ratio in appropriately selected patients. The following case illustrates a previously undocumented danger, namely, the potential for incomplete correction. A thorough transesophageal examination performed at the time of the planned atrial defect closure suggested the presence of a partial anomalous pulmonary vein insertion, which was then appropriately documented and the incomplete closure was averted.
• Herron, S. B., Lax, D., & Zamora, R. (2004). Successful thrombolysis of acute left atrial thrombi in two pediatric patients following interventional cardiac catheterization. The Journal of invasive cardiology, 16(1), 35-9.
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  Acute left atrial intracardiac thrombi require aggressive therapy due to the risk of embolization and cerebrovascular accidents. Current treatment includes the use of high-dose recombinant tissue plasminogen activator (rTPA), which is associated with significant bleeding complications. We report the successful treatment of two pediatric patients with acute left atrial thrombi following interventional cardiac catheterizations using low-dose rTPA. Echocardiography was used to document the presence of the thrombi and monitor treatment with rTPA infusion at 0.03 mg/kg/hour and heparin. Both patients experienced complete resolution of left atrial thrombi without hemodynamically significant side effects. Low-dose (0.03 mg/kg/hour) rTPA with heparin is an acceptable and safe alternative to high-dose rTPA infusion for intracardiac thrombi in children.
• Klewer, S. E., Samson, R. A., Donnerstein, R. L., Lax, D., Zamora, R., & Goldberg, S. J. (2002). Comparison of accuracy of diagnosis of congenital heart disease by history and physical examination versus echocardiography. The American journal of cardiology, 89(11), 1329-31.
• Friedman Kelly, L., Bender, A. M., Lax, D., & Goldberg, S. J. (1998). Alcohol- and Caffeine-Induced Changes in Mitral Valve Echo Morphology and Auscultation in Healthy Females. Echocardiography (Mount Kisco, N.Y.), 15(6), 519-526.
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  Mitral valve prolapse (MVP) is a common cardiac valve abnormality that affects women more frequently than men. We have shown that mild dehydration induces echocardiographic signs of MVP in healthy females more frequently than in males. The present study investigated whether ethanol and caffeine, two commonly used substances, will induce changes in mitral leaflet morphology in normal subjects and whether these changes are gender dependent. Ten healthy volunteers were examined after ingesting 0.95 g/kg ethanol at breath ethanol values of 0.025% +/- 0.005%, 0.050% +/- 0.005%, and 0.075% (peak) +/- 0.005%, and at decreasing ethanol levels of 0.050% +/- 0.005% and 0.025% +/- 0.005%. Twelve healthy subjects were studied at 1.5, 3, and 4.5 hours after ingesting 5 mg/kg body weight of caffeine in a randomized, double-blind, crossover manner. A significant increase in mitral valve shape index (MVSI) on apical four-chamber view was documented in females following ethanol ingestion at all ethanol levels. These changes were accompanied by auscultatory findings characteristic of MVP. Decreased systemic vascular resistance, and afterload and increased heart rate, also occurred after ethanol ingestion. A significant increase in MVSI occurred on parasternal long axis in females at peak caffeine level; auscultatory findings characteristic of MVP also were documented. MVSI increased slightly on apical four-chamber view in males; however, no male subject developed auscultatory MVP. Body mass index was significantly lower in females (20.8 +/- 0.7 kg/m(2)) versus males (23.7 +/- 0.3 kg/m(2), P < 0.05). All subjects lost weight after caffeine intake; afterload and contractility also were increased. This study documents that ethanol and caffeine, at concentrations similar to those present in social intake, induced significant echo changes in mitral leaflet morphology and auscultation suggestive of MVP in healthy females. These results suggest that in addition to apparent hydration state, recent ethanol or caffeine intake should be taken into consideration before making the diagnosis of MVP.
• Barton, L. L., Lax, D., Shehab, Z., & Keith, J. (1996). Congenital cardiomyopathy associated with human parvovirus B19 infection. American Heart Journal, 133, 131-133.
• Zhang, S. L., Lax, D., Li, Y., Noren, G. R., Staley, N. A., & Einzig, S. (1996). Acetaldehyde induces myocardial iron delocalization and lipid peroxidation: possible mechanism in alcoholic cardiomyopathy. Applied Cardiopulmonary Pathophysiology, 6, 151-159.
• Goldberg, S. J., Lax, D., Peoples, W., & Flinn, C. (1995). The time required to perform pediatric transthoracic echocardiographic studies. Journal of the American Society of Echocardiography, 8, 739-741.
• Zamora, R. R., Lax, D., Donnerstein, R. L., & Lloyd, T. R. (1995). Transcatheter closure of residual atrial septal defect following implantation of buttoned device. Catheterization and Cardiovascular Diagnosis, 36, 242-246.
• Aufderheide, S. R., Lax, D., & Goldberg, S. J. (1994). Gender differences in dehydration induced mitral valve prolapse. American Heart Journal, 129, 83-86.
• Duerbeck, N. B., Lax, D., Chaffin, D. M., & Reed, K. L. (1994). Free radical teratogenicity in phenytoin treated mice.. Journal of Maternal-Fetal Investigation, 4, 159-162.
• Lax, D., Holman, R. T., Johnson, S. B., Zhang, S. L., Li, Y., Noren, G. R., Staley, N. A., & Einzig, S. (1994). Myocardial lipid composition of turkeys with dilated cardiomyopathy. Cardiovascular Research, 28, 407-413.
• Lax, D., Martinez-Zaguilan, R., & Gillies, R. J. (1994). Furazolidone increases thapsigargin sensitive Ca ATPase in chick cardiac myocytes. American Journal of Physiology, 267 (Heart Circ Phyisolol 36)(36), H734-741.
• Lax, D., Eicher, M., & Goldberg, S. J. (1993). Effects of hydration on mitral valve prolapse. American Heart Journal, 126, 415-418.
• Lax, D., & Kukolich, S. G. (1992). Generation of radical anion of furazolidone and its inhibition by glutathione.. Bochemical Medicine and Metabolic Biology, 48, 56-63.
• Lax, D., Eicher, M., & Goldberg, S. J. (1992). Mild dehydration induces mitral valve prolapse in healthy females with prior normal cardiac findings. American Heart Journal, 124, 1533-1540.
• Lax, D., Zhang, S. L., Li, Y., Williams, L., Staley, N., Noren, G. R., & Einzig, S. (1990). Reduced heart lipid peroxidation precedes cardiac dilation in turkeys with naturally occurring cardiomyopathy. Cardiovascular Research, 24(7), 540-546.
• Zhang, S. L., Lax, D., Li, Y., Stejskal, E., Lucas, Jr, R. V., Zhang, H. J., Robertson, P., & Einzig, S. (1990). Anisodamine increases blood flow to the retina-choroid and protects retinal and pancreatic cells against lipid peroxidation. Journal of Ethnopharmacology, 30, 121-134.
• Lax, D., Butto, F., Leonard, S. A., Ring, W. S., & Dunnigan, A. (1989). Occult pulmonary artery associated with failure to thrive and recurrent pneumonia. Angiology, 40, 849-853.
• Lax, D., Zhang, S. L., Li, Y., Williams, L., Berry, J. M., Elsperger, J., Staley, N. A., Noren, G. R., & Einzig, S. (1988). Reduced lipid peroxidation in dilated hearts of cardiomyopathic turkeys. Cardiovascular Research, 22(11), 826-832.