Balloon valvuloplasty for congenital aortic stenosis in pregnancy

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Aortic stenosis at young adult age

Aortic stenosis at young adult age is usually the result of a stenotic bicuspid aortic valve, which is the most common cardiac congenital anomaly. In clinical practice, exercise and pregnancy are important topics. Furthermore, the timing of intervention is under debate, as little information is available on the natural history and outcome after aortic valve replacement in these young adults. In older patients, there is a trend towards earlier intervention. With the increased knowledge of the pathophysiology of aortic stenosis, studies have focused on the dilatation of the ascending aorta with risk of dissection. Recently, it has been suggested that pharmacologic treatment of aortic stenosis could be beneficial for these young adults.

Pregnancy in young women with congenital heart disease: Lesion-specific considerations

Young women with heart disease are increasingly being seen in obstetrical referral centres owing, in large part, to the dramatic improvements in survival of young adults with congenital heart disease in recent years. Although pregnancies in most women with heart disease result in favourable outcomes, there are important exceptions that must be recognized. These exceptions pose a significant mortality risk to the mother and/or the fetus. The present article provides a general framework for the classification of congenital heart lesions in pregnant women as well as a detailed lesion-specific review.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: outflow tract obstruction, coarctation of the aorta, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part II of the guidelines includes recommendations for the care of patients with left ventricular outflow tract obstruction and bicuspid aortic valve disease, coarctation of the aorta, right ventricular outflow tract obstruction, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Pregnancy: Maternal and Fetal Heart Disease

Cardiac disorders complicate less than 1% of all pregnancies. Physiologic changes in pregnancy may mimic heart disease. In order to differentiate these adaptations from pathologic conditions, an in-depth knowledge of cardiovascular physiology is mandatory. A comprehensive history, physical examination, electrocardiogram, chest radiograph, and echocardiogram are sufficient in most cases to confirm the diagnosis. Care of women with cardiac disease begins with preconception counseling. Severe lesions should be taken care of prior to contemplating pregnancy. Management principles for pregnant women are similar to those for the non-pregnant state. A team approach comprised of a maternal fetal medicine specialist, cardiologist, neonatologist, and anesthesiologist is essential to assure optimal outcome for both the mother and the fetus. Although fetal heart disease complicates only a small percentage of pregnancies, congenital heart disease causes more neonatal morbidity and mortality than any other congenital malformation. Unfortunately, screening approaches for fetal heart disease continue to miss a large percentage of cases. This weakness in fetal screening has important clinical implications, because the prenatal detection and diagnosis of congenital heart disease may improve the outcome for many of these fetal patients. In fact, simply the detection of major heart disease prenatally can improve neonatal outcome by avoiding discharge to home of neonates with ductal-dependent congenital heart disease. Fortunately, recent advances in screening techniques, an increased ability to change the prenatal natural history of many forms of fetal heart disease, and an increasing recognition of the importance of a multidisciplinary, team approach to the management of pregnancies complicated with fetal heart disease, together promise to improve the outcome of the fetus with congenital heart disease.

Severe cardiac disease in pregnancy, part II: impact of congenital and acquired cardiac diseases during pregnancy

PURPOSE OF REVIEW

Part II of this review gives an overview of the different maternal cardiac problems during pregnancy and their management, and developments over recent years.

RECENT FINDINGS

Many studies published over the last 5 years provided new insights on different cardiac diseases in pregnancy. Publications discussed in this part of the review on cardiac disease in pregnancy, for example, provide epidemiological data on heart disease during pregnancy in general, and cardiomyopathy and ischemic heart disease in particular. In addition, we discussed the implications of a history of peripartum cardiomyopathy for a subsequent pregnancy, interventional strategies during pregnancy in women with ischemic heart disease, and the role of echocardiography in the evaluation of cardiac disease in pregnancy.

SUMMARY

The prevalence of the different causes of heart disease has shifted towards congenital heart disease by the end of the millennium. In developing countries, relatively rare diseases like rheumatic fever are still common, so these diseases are increasingly 'exported' to developed countries. The group of women with congenital heart disease represents most women with heart disease during pregnancy, followed by rheumatic heart disease. With the exception of patients with Eisenmenger's syndrome, pulmonary vascular obstructive disease, and Marfan's syndrome with aortopathy, maternal death during pregnancy is rare in women with heart disease. Although the risk for mortality is low in pregnant women with preexistent cardiac disease, these women are at increased risk for serious morbidity such as heart failure, arrhythmias, and stroke.

Pregnancy and the cardiovascular system

The cardiovascular system undergoes important adaptations during pregnancy to accommodate for fetal requirements. This causes a hemodynamic burden on patients with underlying heart disease, and is associated with significant morbidity and mortality. Moreover, certain cardiovascular diseases may be due to pregnancy. Although unusual, these diseases can pose a threat to the pregnant woman and her fetus. This review will discuss cardiovascular adaptations to pregnancy as well as the risk of pregnancy in patients with underlying heart disease. It will also provide a brief overview of cardiovascular disorders associated with pregnancy.

Valvular heart disease and pregnancy. A high index of suspicion is important to reduce risks

Pregnant women who have valvular disease represent a major challenge for physicians involved in their care. Careful history taking and physical examination, along with a judicious use of diagnostic tools (mainly echocardiography), can lead to better management and ultimately to excellent outcomes for both mother and baby.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.