Hearts of stone: Rapidly progressive left ventricular myocardial calcifications in severe sepsis: Case series

Rapidly progressive left ventricular myocardial calcification (RPLVMC) is a rare phenomenon of severe sepsis which is associated with long‐term complications like irreversible cardiomyopathy and arrhythmias. To date, only 19 cases have been reported in literature. We present a case series of two patients with RPLVMC which manifested within a period of days in the setting of severe sepsis. Unique to previous case reports, the patients in the current case series had no pre‐existing systemic risk factors such as end‐stage kidney disease or endocrinological dysfunction. This case series aims to increase awareness of RPLVMC in severe sepsis, improve its opportunistic detection on routine medical imaging (namely chest x‐ray and computed tomography), and spur future research to develop potential prevention strategies.


Introduction
Myocardial calcification is a rare phenomenon that can be classified into dystrophic and metastatic calcification. 1 Dystrophic calcification occurs in areas of tissue damage, while metastatic calcification occurs in sepsis, chronic renal failure and endocrinological dysfunction. 1 To date, only 19 cases have been reported in literature.We present two patients with RPLVMC in the setting of severe sepsis that manifested within 10 and 3 days.This case series aims to increase awareness of RPLVMC, improve its opportunistic detection on routine imaging and spur future research into this phenomenon.

Cases series
Patient A is a 41-year-old male admitted to the intensive care unit with severe right-sided pyelonephritis.His urine sample cultured E. coli and blood cultures grew Staph Epidermidis.
Patient B is a 53-year-old male admitted post-abandoned Hartmann's procedure for perforated sigmoid diverticulitis and four-quadrant peritonitis.Both patients had acute kidney injuries, ST elevation on electrocardiogram and elevated serum troponin and phosphate levels (Table 1).
Patient A developed RPLVMC on his day 11 computed tomography abdomen/pelvis (CTA/P), which was absent  Subsequent transthoracic echocardiography examinations were performed.Patient A had mild left ventricular dilatation with moderate regional systolic dysfunction and apical akinesia/dyskinesia.Patient B had mild inferoseptal hypokinesis with moderate left ventricular systolic dysfunction.Further investigations with CT coronary angiogram and invasive coronary angiogram revealed no obstructive coronary artery disease in both patients.
Patient A had persistent myocardial calcification and cardiomegaly 9 years post-admission and had an automatic implantable cardiac defibrillator inserted to    prevent life-threatening arrhythmic events.Patient B passed away during his admission due to critical illness myopathy which resulted in ventilator dependence and circulatory shock.

Discussion
The pathophysiology of RPLVMC in sepsis is not well understood.Proposed mechanisms include the release of cardio-suppressing mediators and alteration of calcium-phosphate metabolism in inflammation and acute kidney injury. 2,3In severe sepsis, transmural ischaemia from increased oxygen demand can lead to the hydrolysis of calcium-containing vesicles and calcium influx to myocardial fibres, causing RPLVMC. 2,4,5This likely explains the electrocardiogram changes and troponin rise in our patients in the absence of obstructive coronary artery disease.
RPLVMC can result in long-term complications including irreversible cardiomyopathy, life-threatening arrhythmia, myocardial wall motion abnormalities and conduction disturbances. 1,2Despite this, the heart is often overlooked in routine radiological assessments.In our patients, early subtle RPLVMC were overlooked in the initial CTA/P and were only picked up in subsequent imaging when RPLVMC became florid.This article hopes to raise awareness of RPLVMC and encourage a more robust and opportunistic assessment of the heart in routine medical imaging studies.This will enable clinicians to embark on prompt appropriate investigations and interventions in a bid to prevent significant ramifications affecting morbidity and mortality.Further studies should also be done to unravel the pathophysiology of RPLVMC which will be pertinent to the development of prevention and management strategies.

Table 1 .
Serum blood investigations including serum calcium, corrected calcium and phosphate of patients A and B in mmol/L 0.75-1.50mmol/L PTH N/A N/A N/A N/A N/A 2.0-8.50 pmol/L