Joan Sanchez-de-Toledo

Perioperative Use of Dexmedetomidine Is Associated With Decreased Incidence of Ventricular and Supraventricular Tachyarrhythmias After Congenital Cardiac Operations

BACKGROUND Postoperative tachyarrhythmias remain a common complication after congenital cardiac operations. Dexmedetomidine (DEX), an α-2 adrenoreceptor agonist, can have a therapeutic role in supraventricular tachyarrhythmias for cardioversion to sinus rhythm or heart rate control. Whether routine perioperative use of DEX decreases the incidence of supraventricular and ventricular tachyarrhythmias was studied. METHODS In this prospective cohort study, 32 pediatric patients undergoing cardiothoracic operations received DEX and were compared with 20 control patients who did not receive DEX. RESULTS Dexmedetomidine was started after anesthesia induction and continued intraoperatively and postoperatively for 38±4 hours (mean dose, 0.76±0.04 μg/kg/h). Ten control patients and 2 DEX patients sustained 16 episodes of tachyarrhythmias (p=0.001), including a 25% vs 0% (p=0.01) incidence of ventricular tachycardia and 25% vs 6% (p=0.05) of supraventricular arrhythmias in the control and DEX group, respectively. Transient complete heart block occurred in 2 control patients and in 1 DEX patient. Control patients had a higher heart rate (141±5 vs 127±3 beats/min, p=0.03), more sinus tachycardia episodes (40% vs 6%; p=0.008), required more antihypertensive drugs with nitroprusside (20±7 vs 4±1 μg/kg; p=0.004) and nicardipine (13±5 vs 2±1 μg/kg; p=0.02), and required more fentanyl (39±8 vs 19±3 μg/kg; p=0.005). CONCLUSIONS Perioperative use of dexmedetomidine is associated with a significantly decreased incidence of ventricular and supraventricular tachyarrhythmias, without significant adverse effects.

Maternal and foetal angiogenic imbalance in congenital heart defects

AIMS Animal models showed that angiogenesis is related to abnormal heart development. Our objectives were to ascertain whether a relationship exists between congenital heart defects (CHDs) and angiogenic/anti-angiogenic imbalance in maternal and foetal blood and study the expression of angiogenic factors in the foetal heart. METHODS AND RESULTS Maternal and cord blood placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) were compared in 65 cases of CHD and 204 normal controls. Angiogenic factor expression and markers of hypoxia were measured in heart tissue from 23 CHD foetuses and 8 controls. In the CHD group, compared with controls, plasma PlGF levels were significantly lower (367 ± 33 vs. 566 ± 26 pg/mL; P < 0.0001) and sFlt-1 significantly higher (2726 ± 450 vs. 1971 ± 130 pg/mL, P = 0.0438). Foetuses with CHD had higher cord plasma sFlt-1 (442 ± 76 vs. 274 ± 26 pg/mL; P = 0.0285) and sEng (6.76 ± 0.42 vs. 4.99 ± 0.49 ng/mL, P = 0.0041) levels. Expression of vascular endothelial growth factor (VEGF), sFlt-1, markers of chronic hypoxia, and antioxidant activity were significantly higher in heart tissue from CHD foetuses compared with normal hearts (VEGF, 1.59-fold; sFlt-1, 1.92-fold; hypoxia inducible factor (HIF)-2α, 1.45-fold; HO-1, 1.62-fold; SOD1, 1.31-fold). CONCLUSION An intrinsically angiogenic impairment exists in CHD that appears to be present in both the maternal and foetal circulation and foetal heart. Our data suggest that an imbalance of angiogenic-antiangiogenic factors is associated with developmental defects of the human heart.

Dexmedetomidine: therapeutic use for the termination of reentrant supraventricular tachycardia.

OBJECTIVES The current drug of choice for reentrant supraventricular tachycardia (SVT) is adenosine followed by verapamil or diltiazem. Although limitations and significant adverse events have been encountered over the years, an alternative effective and safe agent has not been available. Dexmedetomidine has recently been shown to have potential antiarrhythmic effects, and here we describe our experience in the acute termination of reentrant SVT. DESIGN Retrospective case series. SETTING Quaternary University Childrens Hospital, Cardiac Intensive Care Unit. PATIENTS Patients who received dexmedetomidine for SVT in the past 5 years. INTERVENTIONS None. OUTCOME MEASURES SVT episodes terminated with dexmedetomidine were compared with episodes terminated with adenosine. RESULTS Fifteen patients, median age of 10 days (6-16), were given 27 doses of dexmedetomidine, mean dose 0.7 ± 0.3 mcg/kg, for a total of 27 episodes of SVT. Successful termination occurred in 26 episodes (96%) at a median time of 30 seconds (20-35). Duration of sinus pause was 0.6 ± 0.2 seconds, there was one episode of hypotension and no bradycardia and sedation lasted for 34 ± 8 minutes. Five patients received 27 doses of adenosine, with an overall successful cardioversion in 17 patients (63%) (P= .0017). Transient bradycardia and hypotension was seen in three patients (11%), agitation in 16 patients (59%), and broncospasm in one patient. Median sinus pause was 2.5 seconds (2-9) (P < .001). CONCLUSIONS Dexmedetomidine appears to have novel antiarrhythmic properties for the acute termination of reentrant SVT. Although adenosine is very effective, dexmedetomidine may prove to possess a more favorable therapeutic profile with increased effectiveness and fewer side effects.

Bedside Ultrasound for the Diagnosis of Abnormal Diaphragmatic Motion in Children After Heart Surgery.

Objective: To assess the utility of bedside ultrasound combining B- and M-mode in the diagnosis of abnormal diaphragmatic motion in children after heart surgery. Design: Prospective post hoc blinded comparison of ultrasound performed by two different intensivists and fluoroscopy results with electromyography. Setting: Tertiary university hospital. Subjects: Children with suspected abnormal diaphragmatic motion after heart surgery. Interventions: None. Measurements and Main Results: Abnormal diaphragmatic motion was suspected in 26 children. Electromyography confirmed the diagnosis in 20 of 24 children (83.3%). The overall occurrence rate of abnormal diaphragmatic motion during the study period was 7.5%. Median patient age was 5 months (range, 16 d to 14 yr). Sensitivity and specificity of chest ultrasound performed at the bedside by the two intensivists (91% and 92% and 92% and 95%, respectively) were higher than those obtained by fluoroscopy (87% and 83%). Interobserver agreement (k) between both intensivists was 0.957 (95% CI, 0.87–100). Conclusions: Chest ultrasound performed by intensivists is a valid tool for the diagnosis of diaphragmatic paralysis, presenting greater sensitivity and specificity than fluoroscopy. Chest ultrasound should be routinely used after pediatric heart surgery given its reliability, reproducibility, availability, and safety.

Prevention of Opioid Withdrawal Syndrome After Pediatric Heart Transplantation: Usefulness of Dexmedetomidine

obesity, and physical inactivity. After decades of efforts to call attention to the disease burden attributable to cardiovascular risk factors, these findings represent an important step toward their complete and critical description. This epidemiological evidence should be expected to direct the debates on the new challenges for maintaining and promoting cardiovascular health in the coming years, as well as specific actions that enable the application of multidisciplinary approaches to the prevention and management of the risk factors and their associated comorbidities. Given the complexity of this issue and the fact that the interactions among the determinants of health vary from one context to another, progress in the attempts to control cardiovascular risk factors will require sustained efforts on a regional, national, and international scale.

Heart transplantation in pediatric patients with pulmonary hypertension.

Patients with congenital heart disease may have pulmonary hypertension secondary to increased pulmonary flow, persistent hypoxemia, or elevated left-side filling pressures. Persistently elevated pulmonary pressure causes pulmonary vasculature remodeling and pulmonary hypertension refractory to vasodilator therapy. Previous reports have described the anatomic-pathologic changes in pulmonary vasculature and their importance. Pulmonary hypertension may be a contraindication for heart transplantation. However, it is difficult to determine the pulmonary resistance value that should be used to contraindicate heart transplantation. Recommendations for pediatric patients are based on experience with adults, and the latest guidelines establish an upper limit of 6 UW/m after the administration of pulmonary vasodilator therapy. Nevertheless, some authors defend the possibility of heart transplantation at higher values. From December 2008 to December 2013, we performed 22 heart transplantations in pediatric patients, among them, 5 patients with severe pulmonary hypertension. The characteristics of these patients are described in the Table. All patients underwent catheterization prior to transplantation, except for 1 patient whose pulmonary pressure was estimated by echocardiography. Pulmonary resistances were calculated at baseline and after the administration of pulmonary vasodilator therapy (nitric oxide). Patient 4 was on the transplantation waiting list for 2 years, but had considerable clinical deterioration with the development of severe pulmonary hypertension (Table); hence, a decision was made to implant a left ventricular assist device and administer pulmonary vasodilator therapy. One month later, the catheterization was repeated and pulmonary resistances had dropped to 3.5 UW/m and, therefore, the patient was put back on the transplantation waiting list. One patient died in the acute phase of the postoperative period due to humoral rejection. All other patients are alive and progressing well. Two patients (40%) required mechanical assistance, 1 due to humoral rejection and the other due to right ventricular dysfunction. All had moderate-to-severe right ventricular dysfunction and required inotropic support and pulmonary vasodilator therapy. In the patients without pulmonary hypertension, right ventricular dysfunction was observed in 9 of 17 (53%; P < .05). Pulmonary vasodilator therapy was maintained at discharge (oral sildenafil), but all patients discontinued the drug during follow-up. Pulmonary biopsies were obtained in 2 patients (Figure) and showed the entire spectrum of vascular lesions characteristic of pulmonary hypertension, with involvement of preacinar and intraacinar arterial vessels, such as plexiform vasculopathy. A venous condition was also observed in the form of hypertrophy. In 1 patient (Figure A), there was a predominance of medial hypertrophy changes in preacinar vessels and plexiform vasculopathy. In the other patient (Figure B), these changes were less serious, but greater intimal thickening was observed, as well as venous involvement with lymph vessel dilation. Comparison of these patients with those without pulmonary hypertension showed no statistically significant differences in survival: 80% of patients with pulmonary hypertension survived compared with 88% of patients without hypertension, with a mean follow-up of 27 (10-62) and 29 (7-60) months, respectively (P > .5). We did observe a higher incidence of cellular (80% vs 24%; P = .02) and humoral (80% vs 12%; P < .01) rejection in patients with pulmonary hypertension, probably due to the greater complexity in this subgroup: 80% of patients with pulmonary hypertension compared with 29% in those without pulmonary hypertension underwent more than 1 cardiac surgery prior to transplantation, including placement of a ventricular assist device (P = .04). Only 2 patients, 1 in each group, had developed antihuman leukocyte antibodies (HLA) before transplantation. In conclusion, it is difficult to establish a value of pulmonary resistance that could be used to contraindicate heart transplantation. Likewise, when referring to pulmonary resistances, the term irreversible should be used with caution because these resistances Rev Esp Cardiol. 2014;67(8):669–679

Role of Magnetic Resonance Imaging in the Diagnosis of Myocarditis in Children

Acute myocarditis is an inflammatory process of the myocardium. In Spain, the underlying cause is most frequently attributed to viral infection, particularly by Parvovirus B19 and adenovirus. Many patients are asymptomatic although possible presenting symptoms include arrhythmias, syncope, chest pain, sudden death, heart failure, and cardiogenic shock. The mortality rate is 20%, and 11% to 50% of patients progress to dilated cardiomyopathy. The standard procedure for diagnosis is still endomyocardial biopsy. Magnetic resonance imaging can be very useful as it can detect tissue changes characteristic of the disease, such as edema, hyperemia, necrosis, and fibrosis, although experience in pediatric patients is limited. Tissue edema is detected as an increase in T2 signal intensity in a focal or diffuse pattern. Hyperemia presents as an increase in early gadolinium enhancement in T1-weighted images, and the irreversible changes due to lesions (necrosis and fibrosis) as an increase in late enhancement. A patchy pattern unrelated to any vascular territory and involvement of the subepicardium with sparing of the subendocardium can provide a differential diagnosis from ischemia (Figure). The presence of 2 of the 3 criteria offers a diagnostic precision of 78%. With regard to treatment, support measures and treatment of heart failure are the only interventions shown to improve prognosis. In our center, a diagnostic protocol is in force in which magnetic resonance and polymerase chain reactions (PCR) analyses to detect viral agents in blood and tracheal aspirate are performed (the latter only in cases of intubated patients). Endomyocardial biopsy is not devoid of risk, and we only perform it on patients whose condition is deteriorating. High-dose endovenous gammaglobulins are used for treatment in view of their immunomodulatory and antiinflammatory effect. From January 2007 through July 2012, 12 patients were admitted to the intensive care unit diagnosed with acute myocarditis. Diagnosis was established by biopsy (3 patients, 25%) or on the basis of the clinical signs and symptoms with additional tests (echocardiography, electrocardiography, troponin levels, viral PCR) along with a cardiac magnetic resonance scan to confirm the diagnosis. Six of the patients were boys (50%) and 6 girls, with ages ranging from 19 days to 14 years (mean, 3.8 years); 3 patients (25%) were neonates. With regard to the clinical presentation, 10 (83.3%) were in cardiogenic shock requiring inotropic support and 2 (16.6%) had chest pain characteristic of ischemia with ST elevation; 11 patients (91.6%) had substantial systolic dysfunction with a mean [SD] ejection fraction of 32% [10%]. One patient with precordial pain and ST elevation had a normal echocardiography examination (ejection fraction, 60%). Eight patients (66%) required mechanical ventilation and 2 needed circulatory assistance with extracorporeal membrane oxygenation (16.6%). Magnetic resonance imaging was performed early (in the first 10 days) in 10 patients (83.3%). The most important finding was the presence of a patchy hyperintense pattern in the T2-weighted scan, indicative of edema (9 patients, 90%). Late enhancement was not assessed in the 5 youngest patients (50%) as the myocardial signal could not be eliminated and was positive in 4 of the 5 patients (80%) in whom this assessment could be performed. Early enhancement showed a heterogeneous and patchy pattern. Viral PCR was done for all patients. The etiologic study was positive in 7 patients (58%); Parvovirus B19 was positive in 4 patients (33% of the sample). In neonates, the virus isolated was enterovirus in 2 patients (16.6% of the sample) and cytomegalovirus in 1 (8.3%). In 3 patients (25%), endomyocardial biopsy was performed and cardiac PCR was positive, with a good correlation with the blood PCR. Tracheal PCR had a low sensitivity, as it was positive in only 1 of the 8 patients (12.5%) in whom this test was done. Troponin T was elevated in all cases and the creatine kinase MB fraction was elevated in 10 (83.3%). For the mean [SD] follow-up of 398 [155] days, transplant-free survival was 83.3% (10/12). One patient received a transplant 5 months after onset of symptoms, after decompensation, and another patient died in the acute phase during biopsy. Complete recovery was reported in 8 patients (66.6%) and 2 (16.6%) progressed to dilated cardiomyopathy, with improvement in function compared to the time of diagnosis. With regard to the prognostic factors, the patients who recovered fully had a better ejection fraction and less dilatation on admission, although the difference was not statistically significant, possibly because of the small sample size. Right ventricular involvement, described as a factor of poor prognosis, was only present in 2 patients (16.6%). Both these were neonates with pulmonary arterial hypertension and their outcome was favorable. Rev Esp Cardiol. 2013;66(6):500–509

Chest pain as the predominant symptom in myocarditis in children.

Acute myocarditis is an inflammatory process of the myocardium that most frequently affects children and young adults. Its forms of presentation include heart failure, arrhythmia, syncope, and sudden death. One of the most commonly involved viruses is Parvovirus B19, which has a special tropism for endothelial cells and has been associated with episodes of chest pain and isolated diastolic dysfunction.Noninfectious causes include giant cell myocarditis and eosinophilic myocarditis. The definitive diagnosis is histological, but magnetic resonance imaging (MRI) is very useful as a noninvasive diagnostic method. We report 3 patients with precordial pain, electrocardiographic changes and elevation of markers of myocardial damage. The differential diagnosis included acute myocarditis and myocardial ischemia. The analytic study ruled out other causes of chest pain, such as familial hypercholesterolemia. The diagnosis was made with MRI. The first patient was a 10-year-old girl diagnosed with acute lymphoblastic leukemia with reactive eosinophilia. Her blood tests showed leucocytosis with eosinophilia. During the course of the disease, she showed a reduction in level of consciousness, and brain MRI showed lesions compatible with vascular disease. A few days later, she experienced precordial pain, electrocardiographic changes with ST depression in LI, LII, V1-V4 and T-wave inversion in all leads, and an increase in cardiac enzyme levels (maximum values: troponin T, 6.7 mg/L; creatine kinaseMB fraction, 38 mg/L). An echocardiogram showed normal coronary artery anatomy and increased left ventricular thickness (septum 10 mm [Z-score=2.56] and posterior wall 10 mm [Z-score=2.26]) with normal systolic function. The MRI scan showed inflammatory infiltrates in the free wall of the left ventricle and the interventricular septum. The clinical picture was considered to be that of eosinophilic myocarditis. Both the neurological and the cardiac pictures resolved by treating her underlying disease. The second patient was a 14-year-old boy who presented to the emergency department was intense precordial pain, which was oppressive, unrelated to exercise and unaffected by postural changes. At admission, the patient had a fever of 38 8C. The electrocardiogram showed ST elevation in the lower leads (LII, LIII and aVF) and V1 and V2 (Fig. 1). Troponin T was 2.8 mg/L and Rev Esp Cardiol. 2013;66(11):908–915

Lung Ultrasound for Cardiogenic Shock in VA-ECMO

A neonate was referred with a diagnosis of refractory cardiogenic shock resulting from dilated myocardiopathy of unknown origin. Echocardiography showed dilation and severe dysfunction (left ventricular ejection fraction < 10%). Venoarterial extracorporeal membrane oxygenation (VA-ECMO) was started. Subsequent echocardiography showed persistence of dilatation of the left chambers (Figure 1A). Chest X-ray (Figure 1B) and lung ultrasound (Figure 2A) showed bilateral pulmonary edema (asterisks), indicated by the presence of B lines (hyperechogenic stripes perpendicular to the transducer and spreading from the pleural line across the screen) in the lung ultrasound (Figure 2A). Left heart decompression was performed by atrial balloon septostomy and the left atrium decreased in size (Figure 2B), with progressive recovery of ventricular function and resolution of pulmonary edema. Lung ultrasound was performed 48 hours after recovery of the pattern of normal pulmonary aeration, as indicated by chest X-ray (Figure 3A) and ultrasound, which showed the presence of A lines (hyperechogenic stripes parallel to the pleura) without the presence of B lines (arrows), a sign of normal pulmonary aeration (Figure 3B). The patient showed progressive improvement, and decannulation of ECMO was possible 7 days later. Echocardiography showed improvement in left ventricular function, with ejection fraction > 60%. This case illustrates the sensitivity and usefulness of chest ultrasound compared with chest X-ray for monitoring pulmonary edema as it reduces children’s exposure to ionizing radiation. Rev Esp Cardiol. 2018;71(5):393