2009

Jim MH, Chan AO, Tse HF, Lau CP
Correspondence: Dr Man-Hong Jim, jimmanh2002@yahoo.com

ABSTRACT
Introduction Compared with anterior wall myocardial infarction, inferior wall myocardial infarction is generally regarded as being low risk. The aim of this study was to elucidate the clinical factors affecting its inhospital outcome.
Methods From January 1997 to March 2006, 546 consecutive patients who suffered from their first inferior wall myocardial infarction were recruited for the study. The demographic, clinical, electrocardiographical and angiographical characteristics, treatment and medications, complications and inhospital deaths were subjected to univariate analysis. The factors that had a p-value of less than 0.1 were included for multivariate logistic regression analysis. A p-value of less than 0.05 was considered significant. The impact of thrombolysis on clinical outcome in various high-risk patient subsets was also examined.
Results An advanced age of more than 74 years, female gender, lateral wall extension, complete atrioventricular block, bundle branch block, and cardiac free-wall rupture were found to be independent predictors of inhospital mortality, whereas the use of thrombolysis was associated with a favourable outcome. On the other hand, right ventricular infarction and precordial ST-segment depression are not predictive of poor outcome. In addition, thrombolysis reduced inhospital mortality in patients with an age above 64 years, male gender, lateral wall extension, haemodynamically-significant right ventricular infarction and complete atrioventricular block.
Conclusion In inferior wall myocardial infarction, independent predictors of poor inhospital outcome are advanced age, female gender, lateral wall extension, complete atrioventricular block, bundle branch block and cardiac free-wall rupture. The use of thrombolysis is generally beneficial, especially in those of the high-risk subsets.

Keywords: acute myocardial infarction, inferior wall myocardial infarction, myocardial infarction, right ventricular infarction, thrombolysis
Singapore Med J 2009; 50(10): 956-961

Jayasinghe SR, Jayasinghe SH
Correspondence: Prof Rohan Jayasinghe, rohan_jayasinghe@health.qld.gov.au

ABSTRACT
Coronary artery disease (CAD) is fast becoming a major morbidity and mortality burden in the developing world. The magnitude of the problem is predicted to exceed that of the developed world due to the sheer population numbers at risk. The Indian subcontinental ethnicity has been associated with a more severe form of CAD that has its onset at a younger age. This form of coronary disease and its risk factors seem quite different from what has been previously described in studies done among non-Asian Indian populations (mainly Caucasians living in the West). This fact has led to a situation where the current preventative and management protocols that have worked well in the non-Asian Indian populations, have failed to bring about the anticipated control over this disease condition, its progression and its incidence in this population. The time has come to identify the variant of CAD in the Asian Indian ethnic population and the associated metabolic factors, as a separate and distinct entity, and as a unique syndrome. This distinction may facilitate more focused and ethnicity-specific studies to be carried out to unravel the mysteries surrounding the clinical, pathological and molecular biological aspects of the CAD syndrome among Asian Indian ethnics. The outcomes and findings of such investigations may help gain a stranglehold on this rapidly-progressing disease condition among the populations in emerging and densely-populated economies of the South Asian region, as well as among millions of Asian-Indian ethnics living all over the world. Thus we may brace ourselves to better address or even prevent what has been dubbed “the next major clinical epidemic of our times”.

Keywords: atherosclerosis, coronary artery disease, cardiovascular prevention, metabolic syndrome
Singapore Med J 2009; 50(10): 949-955

Biswas SK, Sarai M, Hishida H, Ozaki Y
Correspondence: Dr Shankar Kumar Biswas, biswas_70@yahoo.com

ABSTRACT
Fatty acid oxidation is the most efficient mode of myocardial energy production which requires a large amount of oxygen. Thus, alteration of fatty acid oxidation is considered to be a sensitive marker of ischaemia and myocardial damage. ¹²³I-BMIPP (¹²³I-ß-methylp-iodophenylpentadecanoic acid) is a newly-investigated single-photon branching free fatty acid radiopharmaceutical with slow metabolism; thus, it is well-suited for single-photon emission computed tomography (SPECT). Assessment of fatty acid metabolism by radionuclide techniques has a potential role for the early detection of myocardial ischaemia and the assessment of the severity of ischaemic heart disease. Although stable patients with a healed myocardial infarction may have a relatively good prognosis, risk stratification in the predischarge period should be valuable for deciding upon appropriate management. In this respect, the presence of discordant BMIPP uptake relative to 201Tl perfusion appears to be the best predictor of future cardiac events among all other cardiovascular imaging modalities. Since discordant BMIPP uptake correlates well with redistribution on stress 201Tl imaging and perfusion-metabolism mismatch on positron emission tomography, it is considered that such BMIPP and 201Tl discordance may identify a high-risk subgroup among patients with acute myocardial infarction. A BMIPP scan may reflect prior severe ischaemia after recovery of perfusion, the so-called “ischaemic memory”. Gated BMIPP SPECT has been recently introduced for simultaneous assessment of myocardial metabolism and ventricular function. Such a new technique seems to be valuable for a better understanding of the pathophysiological state of heart failure and cardiomyopathy.

Keywords: acute myocardial infarction, ß-methyl-p-iodophenylpentadecanoic acid scan, fatty acid metabolism, ischaemic memory
Singapore Med J 2009; 50(10): 943-948

Wei HM, Wong P, Hsu LF, Shim W
Correspondence: Dr Winston Shim, winston_shim_sn@nhc.com.sg

ABSTRACT
Stem cell-based cell therapy has emerged as a potentially therapeutic option for patients with acute myocardial infarction (AMI) and heart failure. With the completion of a number of trials using bone marrow (BM)-derived adult stem cells, critical examination of the overall clinical benefits, limitations and potential side effects of this revolutionary treatment will pave the way for future clinical research. At present, clinical trials have been conducted almost exclusively using BM stem cells. The primary endpoints of these trials are mainly safety and feasibility, with secondary endpoints in the efficacy of post-myocardial infarction (MI) cardiac repair. Intervention with BM-derived cells was mainly carried out by endogenously-mobilised BM cells with granulocyte-colony stimulating factor, and more frequently, by intracoronary infusion or direct intramyocardial injection of autologous BM cells. While these studies have been proven safe and feasible without notable side effects, mixed outcomes in terms of clinical benefits have been reported. The major clinical benefits observed are improved cardiac contractile function and suppressed left ventricular negative remodelling, including reduced infarct size and improved cardiac perfusion of infarct zone. Moderate and transient clinical benefits have been mostly observed in studies with intracoronary infusion or direct intramyocardial injection of BM cells. These effects are widely considered to be indirect effects of implanted cells in association with paracrine factors, cellfusion, passive ventricular remodelling, or the responses of endogenous cardiac stem cells. In contrast, evidence of cardiac regeneration characterised by differentiation of implanted stem cells into cardiomyocytes and other cardiac cell lineages, is weak or lacking. To elucidate a clear risk-benefit of this exciting therapy, future studies on the mechanisms of cardiac cell therapy will need to focus on confirming the ideal cell types in relation to dosage and timing for post-MI cardiac repair, developing more effective cell delivery techniques, and devising innovative cell tracking modalities that could unveil the fates of implanted cells such as survival, engraftment and functionality.

Keywords: bone marrow transplantation, cardiac repair, heart failure, myocardial infarction, stem cells
Singapore Med J 2009; 50(10): 935-942

Peh WCG, Ng KH
Correspondence: Prof Wilfred CG Peh, smj.editor@sma.org.sg

ABSTRACT
The manuscript reviewer is a key player in the manuscript processing system and journal publication process. The peer review system is an important component of modern scientific publishing, and is a great help to editors in deciding whether or not a submitted manuscript is suitable for publication. The reviewer’s responsibilities include protecting the integrity of his or her speciality or subspecialty, the reputation of the scientific journal, and the welfare of human and animal subjects, as well as treating the author’s manuscript with respect, fairness and impartiality. The manuscript review should ideally be done in a systemic manner, with components comprising a brief summary and a tabulation of the manuscript analysis under the major headings of strengths, weaknesses, general comments and specific comments.

Keywords: manuscript processing, manuscript review, manuscript submission, medical writing, peer review, scientific paper
Singapore Med J 2009; 50(10): 931-934

Qi J, Gu ZQ, Chen F, Zhang L, Chen JH
Correspondence: Dr Zheng-Qin Gu, docguzq@gmail.com

ABSTRACT
Retroperitoneal chylous effusion after urological surgery is a rare and serious complication. Failure in treatment may result in cachexia, threatening the life of the patient. We present the treatment of two cases of postoperative chyloretroperitoneum with the use of somatostatin, octreotide and total parenteral nutrition. In Case 1, an 87-year-old man, a retroperitoneal lymphatic fistula occurred four days after the resection of the left kidney due to carcinoma, whereas in Case 2, a 56-year-old man, a continuous lymph fistula from the renal fossa occurred one month after resection of the right adrenal pheochromocytoma. Case 1 was treated with intravenous administration of somatostatin, and in Case 2, treatment consisted of subcutaneous administration of octreotide, in combination with total parenteral nutrition and other symptomatic therapies. In both cases, lymph exudation was terminated in about two weeks, and the patients recovered. Somatostatin therapy and total parenteral nutrition can effectively treat chyloretroperitoneum.

Keywords: chylous effusion, chyloretroperi-toneum, octreotide , postoperative chyloretroperitoneum, somatostatin, total parenteral nutrition
Singapore Med J 2009; 50(9): e338-e341

Banihani MN, Al-Azab RS, Waqfi NR, Kharashgah MN, Al Manasra ARA
Correspondence: Dr Mohammed N Banihani, mohbanihani@ hotmail.com

ABSTRACT
Secondary thigh abscesses are rare, and their cause is often obscure. We report a 90-year-old man who complained of a thigh abscess that was found to be secondary to a vesicocutaneous fistula. He had previously sustained a pelvic fracture and vesical injury from a road traffic accident two years prior to this diagnosis.

Keywords: bladder injury, thigh abscess, urinary tract fistula, vesicocutaneous fistula, vesical injury
Singapore Med J 2009; 50(9): e336-e337

Banerji JS, Gopalakrishnan G, Sriram K, Manipadam MT
Correspondence: Dr Banerji John Samuel, johnsbanerji2002@yahoo.co.in

ABSTRACT
Primary localised amyloidosis involving the retroperitoneum is a rare disease. We report a 71-year-old diabetic man who presented with generalised fatigue, malaise and elevated serum creatinine. Investigations confirmed obstructive uropathy secondary to a retroperitoneal mass behind the urinary bladder, causing extrinsic compression of both the ureters, resulting in bilateral hydroureteronephrosis. Following initial bilateral percutaneous nephrostomies to stabilise renal function, a computed tomography-guided biopsy of the pelvic lesion which was done, was suggestive of amyloidosis. We present this case due to the rarity of localised retroperitoneal amyloidosis as a cause of obstructive uropathy.

Keywords: amyloidosis, localised retroperitoneal amyloidosis, obstructive uropathy, retroperitoneum, retrovesical amyloid deposition
Singapore Med J 2009; 50(9): e332-e335

Ngan KW, Shaari S, Subramaniam T
Correspondence: Dr Ngan Kah Wai, ngan751@hotmail.com.tw

ABSTRACT
We report a six-year-old Malay girl who presented with a right retroperitoneal tumour that measured 7.5 cm in diameter. A wide excision of the lesion was performed. The tumour was separated from a normal-appearing right kidney by a capsule. Microscopically, this well-encapsulated tumour was composed of classical triphasic components: epithelial, mesenchymal and blastemal areas. The immunohistochemical study showed WT1 expression in the blastemal area. Thus, a diagnosis of Wilms’ tumour with favourable histology was made. The patient was well for 12 months. Extrarenal Wilms’ tumour is uncommon, with the majority of cases occurring in the retroperitoneal and inguinal areas. Wilms’ tumour that is not arising from the intrarenal area but shares a common capsule with the ipsilateral kidney, is even rarer. Indeed, our case would be more appropriately classified as juxtarenal/pararenal Wilms’ tumour. Despite its rarity, an extrarenal or even juxtarenal/pararenal Wilms’ tumour should be included in the differential diagnosis of retroperitoneal tumour.

Keywords: extrarenal Wilms’ tumour, juxtarenal Wilms’ tumour, pararenal Wilms’ tumour, retroperitoneal tumour, Wilms’ tumour
Singapore Med J 2009; 50(9): e329-e331