Perinatal renal ischemia resulting in hypertensive cardiomyopathy

Hypertension: An Important But Reversible Cause of Systolic Dysfunction in a Cohort of Pediatric Patients

Cardiac dysfunction due to hypertension (CDHTN) in pediatrics is not well described. We aimed to describe the presentation and outcomes of pediatric CDHTN and identify clinical features associated with resolution of dysfunction. A single-center retrospective cohort study of patients ≤ 21 years with CDHTN from January 2005-September 2020 was performed. Patients with systolic dysfunction without another cause, blood pressure > 95th percentile, and physician judgment that dysfunction was secondary to hypertension were included. Demographics, clinical characteristics, echocardiographic findings, and outcomes were examined using Fisher's exact and Mann-Whitney U tests. Multiple correspondence analysis was used to explore the relationship of resolution of dysfunction to clinical features. Thirty-four patients were analyzed at a median age of 10.9 (IQR 0.3-16.9) years. Patients were divided into groups < 1 year (n = 12) and ≥ 1 year (n = 22). Causes of hypertension were varied by age, with renovascular disease most common in infants (42%) and medical renal disease most common in older patients (77%). Echocardiography demonstrated mild LV dilation (median LV end-diastolic z-score 2.6) and mild LV hypertrophy (median LV mass z-score 2.4). Most patients (81%) had resolution of dysfunction, particularly infants (92%). One patient died and one patient was listed for heart transplant. None required mechanical circulatory support (MCS). No clinical features were statistically associated with resolution of dysfunction. Hypertension is an important but reversible cause of systolic dysfunction in children. Patients are likely to recover with low mortality and low utilization of MCS or transplantation. Further studies are needed to confirm features associated with resolution of dysfunction.

Hypertensive crisis in children and adolescents

Hypertensive crisis is a relatively rare condition in children. However, if not treated, it might be life-threatening and lead to irreversible damage of vital organs. Clinical presentation of patients with hypertensive crisis can vary from very mild (hypertensive urgency) to severe symptoms (hypertensive emergency) despite similarly high blood pressure (BP). Individualized assessment of patients presenting with high BP with emphasis on the evaluation of end-organ damage rather than on the specific BP number is a key in guiding physician's initial management of a hypertensive crisis. The main aim of the treatment of hypertensive crisis is the prevention or treatment of life-threatening complications of hypertension-induced organ dysfunction, including neurologic, ophthalmologic, renal, and cardiac complications. While the treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to these organs, it should not be at a too fast rate to cause hypoperfusion of vital organs by an excessively rapid reduction of BP. Thus, intravenous continuous infusions rather than intravenous boluses of antihypertensive medications should be the preferable mode of initial treatment of children with hypertensive emergency.

Neonatal circulatory failure due to acute hypertensive crisis: clinical and echocardiographic clues

OBJECTIVE

Circulatory failure due to acute arterial hypertension in the neonatal period is rare. This study was undertaken to assess the clinical and echocardiographic manifestations of circulatory failure resulting from acute neonatal hypertensive crisis.

METHODS

Neonatal and cardiology databases from 2007 to 2010 were reviewed. An established diagnosis of circulatory failure due to neonatal hypertension before the age of 14 days was required for inclusion. Six patients were identified.

RESULTS

Five patients presented with circulatory failure due to an acute hypertensive crisis. The median age at presentation was 8.5 days (range: 6.0-11.0) with a median body weight of 3.58 kg (range: 0.86-4.70). Echocardiography demonstrated mild left ventricular dysfunction [median shortening fraction (SF) 25%, range 10-30] and mild aortic regurgitation in 83% (5/6) of patients. One patient with left ventricular dysfunction (SF = 17%) had a large apical thrombus. Two patients were hypotensive, and hypertension only became evident after restoration of cardiac output. Administration of intravenous milrinone was successful, with rapid improvement of the clinical condition. Left ventricular function normalised in all survivors.

CONCLUSION

Early neonatal circulatory collapse due to arterial hypertension is a rare but potentially life-threatening condition. At presentation, hypotension, especially in the presence of a dysfunctional left ventricle, does not exclude a hypertensive crisis being the cause of circulatory failure. The echocardiographic presence of mild aortic regurgitation combined with left ventricular hypocontractility in a structurally normal heart should alert the physician to the presence of underlying hypertension.

Hypertensive crisis in children

Hypertensive crisis is rare in children and is usually secondary to an underlying disease. There is strong evidence that the renin-angiotensin system plays an important role in the genesis of hypertensive crisis. An important principle in the management of children with hypertensive crisis is to determine if severe hypertension is chronic, acute, or acute-on-chronic. When it is associated with signs of end-organ damage such as encephalopathy, congestive cardiac failure or renal failure, there is an emergent need to lower blood pressures to 25-30% of the original value and then accomplish a gradual reduction in blood pressure. Precipitous drops in blood pressure can result in impairment of perfusion of vital organs. Medications commonly used to treat hypertensive crisis in children are nicardipine, labetalol and sodium nitroprusside. In this review, we discuss the pathophysiology, differential diagnosis and recent developments in management of hypertensive crisis in children.

Unmasking of neonatal renovascular hypertension by milrinone used for cardiac dysfunction

A neonate initially presented with heart failure, with severe cardiac dysfunction confirmed by echocardiography, at 3 days of age. Blood pressure at presentation was in the high normal range. It was not until there was a rapid improvement of left-ventricular function on intravenous milrinone that the infant was noted to be hypertensive on day of life 7. It is noteworthy that milrinone, a drug with vasodilator and inotropic properties, paradoxically unmasked hypertension by rapidly improving left-ventricular function. Subsequent work-up showed the etiology of hypertension to be left renal artery stenosis. We present this case to alert clinicians to the rarer causes of left-ventricular dysfunction and to point out that its etiology, i.e., hypertension, may not be apparent until there is improvement in the systolic function of the left ventricle.

Postrenal biopsy AVM leading to severe hypertension and dilated cardiomyopathy

A 3-year-old girl with Alport syndrome presented with decompensated heart failure from hypertension-induced cardiomyopathy 6 months following renal biopsy. Selective renal angiography revealed a large left renal arteriovenous fistula (AVF) with poor perfusion to the left renal parenchyma. The AVF was treated by transcatheter embolization using an Amplatzer vascular plug. Her blood pressure normalized after embolization, and her cardiac function normalized over the following 4 months.

Renovascular hypertension commencing during fetal life

We report three infants with severe, early hypertension due to unilateral renovascular disease, whose cardiovascular changes, or polycythaemia, or both, indicated they had been affected as fetuses. All underwent unilateral nephrectomy, and had a similar histology, with patchy areas having relatively normal glomeruli but immature proximal tubules. This pattern may be a marker for renovascular disease in fetal life.

An unusual case of severe therapy-resistant hypertension in a newborn

Hypertension can occur in up to 2% of neonates, and the spectrum of potential causes is broad. Prompt and thorough evaluation with a main focus on kidney disease is key for appropriate therapy. Here we describe a 2-day-old neonate with feeding intolerance and elevated blood pressure readings. Within 24 hours after birth, the infant's blood pressure increased significantly, with sustained mean arterial pressure >85. Renal Doppler ultrasound showed decreased venous blood flow in the right kidney with an abnormal Doppler wave form suggestive of unilateral renal venous thrombosis. Despite aggressive antihypertensive therapy including hydralazine and enalaprilat, hypertension remained sustained. On day-of-life 4, the infant developed clinical signs of hypertensive encephalopathy and significant cardiac dysfunction. A renal angiography showed complete, likely thrombotic occlusion of the right renal artery. Renal MAG3 imaging showed minimal function of the affected kidney, and a nephrectomy secondary to medically uncontrollable hypertension and worsening cardiac dysfunction was performed. The child is developing normally in all aspects on follow-up evaluations at 6 months and 1 year of age. Reevaluation of the working diagnosis in neonates with hypertension can be necessary to optimize the outcome. The overall prognosis can be excellent even in newborns with profound cardiac and neurologic involvement.

Presentation and echocardiographic markers of neonatal hypertensive cardiomyopathy

BACKGROUND

Systemic hypertension is a rare but important cause of neonatal heart failure. It is critical that this etiology be recognized and distinguished from other causes of myocardial dysfunction in young infants, because diagnostic studies, treatments, and prognoses are quite different.

METHODS

Between 1991 and 2005, 11 neonates were diagnosed as having neonatal cardiomyopathy and systemic hypertension through retrospective review of the Children's Hospital of Wisconsin database.

RESULTS

All infants in the cohort were found to have systemic hypertension (blood pressure of > 95th percentile for gestational age and weight). Causes included renovascular disease (n = 9), aortic obstruction secondary to thrombus (n = 1), and steroid use (n = 1). Echocardiography was performed at presentation for all patients because of cardiomegaly and/or hypertension. Echocardiographic findings were consistently striking for (1) left ventricular systolic dysfunction without chamber dilation, (2) concentric left ventricular hypertrophy, (3) left atrial dilation, and (4) aortomegaly. No anatomic aortic arch obstruction was identified, but Doppler findings for the descending thoracic aorta were uniformly consistent with elevated systemic vascular resistance. One patient died as a result of overwhelming thrombotic disease; all other patients responded to afterload reduction therapy with normalization of left ventricular systolic function during infancy.

CONCLUSIONS

Hypertensive cardiomyopathy can present in neonates with nonspecific symptoms and systemic hypertension. Because sometimes hypertension in infants is ignored or misinterpreted as agitation, echocardiography can provide critical markers of the disease.

Percutaneous transluminal angioplasty for renovascular hypertension in a neonate

AIM

To report on the first case of successful percutaneous transluminal renal artery angioplasty in a neonate.

METHODS

CASE REPORT

a 5-d-old neonate was admitted with cardiorespiratory failure. Monitoring of blood pressure revealed severe arterial hypertension. Doppler sonography detected stenotic flow in the right renal artery. A (99m)Tc-MAG3 scan revealed highly diminished elimination by the right kidney. Selective renin levels were 23,968 ng/l in the right and 3770 ng/l in the left renal vein and the aorta. Percutaneous transluminal angioplasty using a 2 x 10 mm balloon catheter was performed on the 8th day of life.

RESULTS

The patient was discharged from hospital normotensive without anti-hypertensive medication. During 8 mo follow-up the blood pressure remained normal, Doppler sonography revealed no recurrent artery stenosis, and renal function improved.

CONCLUSION

Neonatal percutaneous transluminal angioplasty for renal artery stenosis may be feasible in selected patients.