Sixteen years after a long admission for a serious occupational accident, a 38-year-old man presented with intermittent atypical chest pain. Upon investigations a retained fragment of a pulmonary artery catheter was found in the right ventricle. Throughout the years between his accident and the current presentation he did not have any symptoms or signs of complications associated with the retained catheter such as arrhythmia, sepsis or thromboembolism. Upon presenting his case at the medical/surgical multidisciplinary meeting it was decided that the probability of complications occurring at this stage was low as the catheter fragment would have endothelialised and the risk of retrieval would outweigh the benefits. This scenario highlighted the importance of understanding the possible long-term complications of retained catheter fragments, the importance of being aware of the limitation of these devices and the need to be more vigilant in the emergency setting.
Pre-conditioning is an exciting physiological phenomenon that, despite great efforts, has so far resisted translation to mainstream clinical medicine. Many potential triggers (e.g., ischemia of the organ in question or a remote organ, many different drugs) have been investigated, but recent work has implicated activation of mitochondrial aldehyde dehydrogenase (ALDH2) as central to the process. A genetic polymorphism, known as ALDH2*2, is common worldwide (present in up to 40% of Han Chinese people) and produces a functionally different enzyme. The authors used a variety of protocols in the human ischemic forearm model, in participants with both enzyme types, to assess cytoprotection with low-dose sodium nitrite and attempt to further elucidate the role of ALDH2.
This chapter assesses myocardial energetics. The heart requires very large amounts of energy, cycling many times its own weight in ATP daily, and uses a variable combination of carbohydrates, lipids, lactate, and amino acids as fuel. A key feature of the healthy heart is ‘metabolic flexibility’, i.e. the ability to use different substrates according to circumstances. As the syndrome of heart failure progresses, a steady downregulation of all aspects of cardiac metabolism may be seen. In extreme disease states, a fundamental deficiency in ATP can be demonstrated, but more subtle metabolic abnormalities are detectable at an earlier stage. Additionally, there are multiple downstream disturbances in mitochondrial function, in the high-energy phosphate pool and in excitation–contraction coupling. Ultimately, the detection of abnormalities of myocardial metabolism and energetics has spurred an interest in therapeutic modulation of metabolism in heart failure. This is attractive, as potentially such modulation would improve myocardial efficiency without the need for increased fuel delivery. Such therapies could have an additive effect to current heart failure management which generally relies on correction of the maladaptive neurohumoral consequences of the heart failure syndrome.
A grossly obese woman was wrongly diagnosed throughout her adult life of having lymphoedema. Her condition was subsequently confirmed as lipoedema, an entirely different condition, which is noted in medical text books but is seldom taught to medical students or to general practitioners. The condition is caused by abnormal deposition of adipose tissue in the extremities (usually the lower limbs) and almost exclusively affects women. It often starts at puberty or may occur after pregnancy. The exact aetiology is not yet understood but genetic and hormonal factors may be implicated. The problem is that misdiagnosis leads to inappropriate tests and improper treatment to the patient. When recognised it is often too late to do anything for the patient and they become highly dependent on social care. This case describes how the diagnosis can be confirmed through an ultrasound image and illustrates the need for early recognition to facilitate specialist care.
A 71-year-old man was transferred to the extraction centre with Staphylococcus aureus endocarditis and a 3.5 × 1.7 cm vegetation adherent to the ventricular lead of his 7-year-old secondary-prevention dual chamber ICD (see Panel A and Supplementary material online, Videos S1–S3). He had been initially managed medically but the vegetation …
Sudden death and cardiac arrest frequently occur without explanation, even after a thorough clinical evaluation. Calcium release deficiency syndrome (CRDS), a life-threatening genetic arrhythmia syndrome, is undetectable with standard testing and leads to unexplained cardiac arrest.
A novel familial arrhythmia syndrome, cardiac ryanodine receptor (RyR2) calcium release deficiency syndrome (CRDS), has recently been described. We evaluated a large and well characterized family to assess provocation testing, risk factor stratification and response to therapy in CRDS.We present a family with multiple unheralded sudden cardiac deaths and aborted cardiac arrests, primarily in children and young adults, with no clear phenotype on standard clinical testing.Genetic analysis, including whole genome sequencing, firmly established that a missense mutation in RYR2, Ala4142Thr, was the underlying cause of disease in the family. Functional study of the variant in a cell model showed RyR2 loss-of-function, indicating that the family was affected by CRDS. EPS (Electrophysiological Study) was undertaken in 9 subjects known to carry the mutation, including a survivor of aborted sudden cardiac death, and the effects of flecainide alone and in combination with metoprolol were tested. There was a clear gradation in inducibility of nonsustained and sustained ventricular arrhythmia between subjects at EPS, with the survivor of aborted sudden cardiac death being the most inducible subject. Administration of flecainide substantially reduced arrhythmia inducibility in this subject and abolished arrhythmia in all others. Finally, the effects of additional metoprolol were tested; it increased inducibility in 4/9 subjects.The Ala4142Thr mutation of RYR2 causes the novel heritable arrhythmia syndrome CRDS, which is characterized by familial sudden death in the absence of prior symptoms or a recognizable phenotype on ambulatory monitoring or exercise stress testing. We increase the experience of a specific EPS protocol in human subjects and show that it is helpful in establishing the clinical status of gene carriers, with potential utility for risk stratification. Our data provide evidence that flecainide is protective in human subjects with CRDS, consistent with the effect previously shown in a mouse model.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)