Dilated cardiomyopathy due to hypocalcaemic rickets: is it always a reversible condition?

Cardiovascular disease in low- and middle-income countries associated with environmental factors

There is a growing recognition that the profound environmental changes that have occurred over the past century pose threats to human health. Many of these environmental factors, including air pollution, noise pollution, as well as exposure to metals such as arsenic, cadmium, lead, and other metals, are particularly detrimental to the cardiovascular health of people living in low-to-middle income countries (LMICs). Low-to-middle income countries are likely to be disproportionally burdened by cardiovascular diseases provoked by environmental factors. Moreover, they have the least capacity to address the core drivers and consequences of this phenomenon. This review summarizes the impact of environmental factors such as climate change, air pollution, and metal exposure on the cardiovascular system, and how these specifically affect people living in LMICs. It also outlines how behaviour changes and interventions that reduce environmental pollution would have significant effects on the cardiovascular health of those from LMICs, and globally.

Nutritional Heart Disease and Cardiomyopathies: JACC Focus Seminar 4/4

This JACC Focus Seminar provides an overview of and highlights recently published research on cardiomyopathies and nutritional heart disease that have a higher prevalence in tropical regions. The development of tropical cardiomyopathies and nutritional cardiovascular disease (CVD) is complicated by high rates of poverty, fragmented health care systems, and suboptimal access to health care because of socioeconomic inequalities, leading to the fact that children, adolescents, and young adults are disproportionally affected. Such tropical cardiomyopathies and nutritional CVD that have not been prevalent in high-income countries in the past decades are now reemerging. When treating migrants or refugees, it is important for attending physicians to consider the burden of endemic diseases in the countries of origin and the likelihood that such patients might be affected. In this review, the authors propose an approach for adequate diagnostic work-up leading to appropriate care for those with suspected or confirmed tropical cardiomyopathies and nutritional CVD.

Role of Cardiac Magnetic Resonance Imaging in Hypocalcemia-Induced Dilated Cardiomyopathy in Pediatric Population

Background  Hypocalcemia is a rare reversible cause of dilated cardiomyopathy in pediatric population. Myocarditis is another more frequent cause of cardiomyopathy with overlapping presenting features. Cardiac magnetic resonance imaging (CMRI) is a vital modality capable of tissue characterization for the evaluation of cardiomyopathy. The present study is the first attempt to determine if any specific characteristics on CMR exist in patients with hypocalcemic dilated cardiomyopathy.

Methods  A retrospective analysis of 10 cases of hypocalcemic dilated cardiomyopathy (August 2012–August 2019), among which CMRI of nine patients were analyzed. Patients were categorized in to three categories; category 1 defined as absence of edema and late gadolinium enhancement (LGE), category 2 having edema only, and category 3 with presence of both edema and LGE. A diagnosis of myocarditis was considered if both edema and LGE were present.

Results  The mean age of the cohort was 5.5 ± 3.3 months. The mean ejection fraction of the cohort was 20.5 ± 6.85% that improved significantly to 35.22 ± 9.3% at the time of discharge. Five of nine patients had no edema or LGE (category 1), whereas two patients each were categorized into category 2 and 3. All cases in category 1 had normalized ventricular function on follow-up. One patient in category 2 had normal ejection fraction and one was lost to follow-up. Out of the two patients in category 3, there was one mortality and another was lost to follow-up. Of the six patients at follow-up (19 ± 11.0 months), the mean left ventricle ejection fraction improved to 56.5 ± 6.1%.

Conclusion  Hypocalcemic dilated cardiomyopathy has a favorable outcome on rapid initiation of treatment. CMR can be utilized for further prognostication of these patients. Absence of edema and LGE predicts a good outcome, whereas presence of LGE and/or edema either indicates a worse prognosis or an underlying coexistent myocarditis warranting an early myocardial biopsy.

Clinical, biochemical, and echocardiographic evaluation of neonates with vitamin D deficiency due to maternal vitamin D deficiency

OBJECTIVE

There are a few number of case reports and small-scale case series reporting dilated cardiomyopathy due to vitamin D-deficient rickets. The present study evaluates the clinical, biochemical, and echocardiographic features of neonates with vitamin D deficiency.

PATIENTS AND METHODS

In this prospective single-arm observational study, echocardiographic evaluation was performed on all patients before vitamin D3 and calcium replacement. Following remission of biochemical features of vitamin D deficiency, control echocardiography was performed. Biochemical and echocardiographic characteristics of the present cohort were compared with those of 27 previously published cases with dilated cardiomyopathy due to vitamin D deficiency.

RESULTS

The study included 148 cases (95 males). In the echocardiographic evaluation, none of the patients had dilated cardiomyopathy. All of the mothers were also vitamin D deficient and treated accordingly. Comparison of patients with normocalcaemia and hypocalcaemia at presentation revealed no statistically significant difference between the ejection fraction and shortening fraction, while left ventricle end-diastolic diameter and left ventricle end-systolic diameter were higher in patients with hypocalcaemia. Previously published historical cases were older and had more severe biochemical features of vitamin D deficiency.

CONCLUSION

To the best of our knowledge, in this first and largest cohort of neonates with vitamin D deficiency, we did not detect dilated cardiomyopathy. Early recognition and detection before developing actual rickets and preventing prolonged hypocalcaemia are critically important to alleviate cardiac complications.

Nutritional Rickets and Osteomalacia in the Twenty-first Century: Revised Concepts, Public Health, and Prevention Strategies

PURPOSE OF REVIEW

Nutritional rickets and osteomalacia are common in dark-skinned and migrant populations. Their global incidence is rising due to changing population demographics, failing prevention policies and missing implementation strategies. The calcium deprivation spectrum has hypocalcaemic (seizures, tetany and dilated cardiomyopathy) and late hypophosphataemic (rickets, osteomalacia and muscle weakness) complications. This article reviews sustainable prevention strategies and identifies areas for future research.

RECENT FINDINGS

The global rickets consensus recognises the equal contribution of vitamin D and dietary calcium in the causation of calcium deprivation and provides a three stage categorisation for sufficiency, insufficiency and deficiency. For rickets prevention, 400 IU daily is recommended for all infants from birth and 600 IU in pregnancy, alongside monitoring in antenatal and child health surveillance programmes. High-risk populations require lifelong supplementation and food fortification with vitamin D or calcium. Future research should identify the true prevalence of rickets and osteomalacia, their role in bone fragility and infant mortality, and best screening and public health prevention tools.

Reversible Dilated Cardiomyopathy Due to Combination of Vitamin D-Deficient Rickets and Primary Hypomagnesemia in an 11-Month-Old Infant

Vitamin D-deficient rickets is still an important and common health problem in developing countries. Since calcium is an essential ion for cardiac muscle contraction, calcium deficiency caused by rickets can cause secondary dilated cardiomyopathy. This situation can be exacerbated by coexisting hypomagnesemia. Here, we report a case of dilated cardiomyopathy due to hypocalcemia induced by vitamin D-deficient rickets and accompanying primary hypomagnesemia in an infant whose cardiomyopathy was successfully treated by replacement of calcium, vitamin D, and magnesium. In addition to genetic causes, viral infections, and idiopathic factors, metabolic abnormalities are important etiologic factors in pathogenesis of dilated cardiomyopathy and since they are treatable, prompt diagnosis of these disorders is crucial.

Life-threatening Dilated Cardiomyopathy Induced by Late-onset Neonatal Hypocalcemia

Neonatal seizures caused by hypocalcemia may be associated with cardiopulmonary dysfunction and may require specific management other than calcium supplementation. Severe dilated cardiomyopathy is an extremely rare complication in neonatal hypocalcemia and often results in high morbidity and mortality. We report here a 14-day-old neonate presenting with a gradually increasing frequency of tonic seizures. After admission, arterial desaturation was found despite supplying oxygen (4 L/min) through nasal prongs and the patient developed life-threatening respiratory distress and heart failure secondary to dilated cardiomyopathy. His critical cardiopulmonary derangements rapidly improved after respiratory support, the administration of diuretic and inotropic drugs, and the correction of his hypocalcemia and hypomagnesemia. The patient responded to treatment and was well during the 1-year follow-up period. We present this unique case history of seizure, respiratory distress, and heart failure induced by transient hypocalcemia to remind clinicians about the importance of this rare, life-threatening, but reversible, disorder.