Heart Attack and LVD

What Is a Heart Attack?
According to the American Heart Association, someone dies from heart and blood vessel disease every 34 seconds in the US.
It is America’s number-one killer. A "coronary" or heart attack occurs when the blood flow to a part of the heart is blocked. This blockage often results from a clot because the arteries that supply the heart with blood are affected by fat, cholesterol, and other substances called plaque.
If the plaque breaks open and a blood clot forms, it can block the flow of blood to the heart. Without blood to nourish the muscle in the heart, it begins to die. The longer the artery remains blocked, the more damage is done until the muscle supplied by that artery is completely dead.

What is LVD?
The left lower chamber (ventricle) of the heart receives blood from the left atrium and pumps it out to the body under high pressure through the aorta.
When the heart muscle tissue has been scarred from a heart attack to the point it is not as effective as it should be, it does not pump enough blood to the rest of the body. This is known as left ventricular dysfunction or LVD.
LVD is often diagnosed after a heart attack. In some cases, it develops over time and is not diagnosed right away. There may be no symptoms with LVD, but they could develop if the heart muscle continues to weaken. This will lead to symptoms of heart failure.


Major Causes and Risk Factors
The plaque that builds up in the arteries can eventually rupture and cause a blood clot in a coronary artery.
This is a major, underlying cause of heart attacks. Factors that increase your risk for narrowed coronary arteries - and thus a heart attack - include family history of heart disease, a high level of LDL cholesterol (the "bad" cholesterol), high blood pressure, smoking, obesity, and physical inactivity.

These risk factors are described in detail below:

• High blood pressure is usually defined as 140/90 mmHg or more. Slight fluctuations are normal. However, if the pressure remains high for a long period of time, there is increased danger that it will speed up atherosclerosis or the buildup of fatty deposits in the blood vessels.
• High cholesterol is one of the main reasons that blood vessels become clogged and narrower than they should be. If you have too much cholesterol, you increase the risk of narrowing your arteries and thus the risk of having a heart attack. Some cholesterol, called high density lipoprotein (HDL) cholesterol, is good; but the low density type (LDL) is bad. This comes mainly from foods that are high in fats and cholesterol.
• Cigarette smoking and exposure to second-hand smoke can do more damage than just cause lung cancer. It is also responsible for depositing cholesterol on the walls of the blood vessels.
• Not enough exercise can be a risk factor for heart attacks. Physical activity and regular exercise help to keep your blood pressure in control and also help to reduce your cholesterol.
• Being overweight is a risk factor for heart attacks because it can indicate that you do not get enough exercise and do not eat properly. People who also have diabetes may be at increased risk for heart disease. Diabetes refers to the inability of the body to produce enough of a hormone called insulin or the inability of your body’s insulin to process blood sugar properly. Having diabetes can result in increased cholesterol levels.
• Too much stress and tension in your life can increase your blood pressure, which can put you at risk for a heart attack.
• Drinking too much alcohol can raise your blood pressure and triglyceride levels, and that can increase your risk for a heart attack.
• Of course, some people are more prone to heart attack because of family history. If you have close relatives who have had heart attacks, you might be at risk as well.
  

http://www.coreg.com/ncmp/heartattack/causes_of_heart_attack.htm

Transthoracic Doppler echocardiography

Noninvasive Visualization and Measurement of Middle Cardiac Vein Flow by Transthoracic Doppler Echocardiography

Kenji Harada, Masamichi Tamura and Manatoma Toyono
Department of Pediatrics, Akita University School of Medicine, 010-8543 Akita, Japan

Transthoracic Doppler echocardiography offers a noninvasive approach for imaging posterior descending coronary artery (PD) running in the posterior longitudinal sulcus along the middle cardiac vein (MCV).

To evaluate whether the MCV flow velocity reserve can reflect the PD flow reserve, 22 children with various heart diseases were examined using transthoracic Doppler echocardiography.

Introduction of a modified transthoracic two chamber view with the transducer rotated counterclockwise and angulated posteriorly allows visualization of the MCV and PD. Peak systolic flow velocity and average peak systolic flow velocity in the MCV and peak diastolic flow velocity and average peak diastolic flow velocity in the PD were measured at rest and hyperemic conditions (intravenous administration of adenosine of 0.16 mg/kg/min).

Coronary flow reserve was defined as the ratio of peak hyperemic to basal average peak flow velocity. ATP infusion induced significant increases in the peak systolic flow velocity and average peak systolic flow velocity in the MCV. The mean MCV flow velocity reserve in the patients was 1.94 ± 0.44. Significant increases in the peak diastolic flow velocity and the average peak diastolic flow velocity in the PD were also observed during ATP infusion, and the mean PD flow velocity reserve (2.19 ± 0.62) was significantly higher than the GCV flow velocity reserve (p < 0.0001).

There was a good correlation between the MCV flow velocity reserve and PD flow velocity reserve (r = 0.86, p <>

However, the degree of the MCV flow during hyperemia was less than that of the PD flow. This underestimation should be considered when the reactive hyperemic response is evaluated from the MCV flow velocity.

Keywords. Transthoracic Doppler echocardiography - Coronary flow reserve - Posterior descending coronary artery - Middle cardiac vein

Pediatric Cardiology

Volume 27, Number 6 / December, 2006, p. 679-684

Familial atrial fibrillation

Atrial Fibrillation with Hyperthyroidism in a 14-Year-Old Male

Hisashi Takasugi, Kota Ao, Tetsuya Sato, Akihiko Maeda, Taisuke Okada and Hiroshi Wakiguchi
Department of Pediatrics, Program of Baio-signaling and Infection Control, Kochi Medical School, Kochi University, Kohasu, Oko, Nankoku Kochi, 783-8505, Japan

Atrial fibrillation is an uncommon feature of hyperthyroidism in childhood. We report a 14-year-old male who was referred to our hospital with hyperthyroidism and atrial fibrillation. He had a family history of atrial fibrillation. Spontaneous conversion of atrial fibrillation to sinus rhythm occurred 20 weeks after achieving euthyroid state by an antithyroid agent and a β-blocker. Atrial fibrillation reoccurred after reduction of antithyroid medication and persisted for 19 weeks. Successful electrical cardioversion was performed resulting in conversion of heart rhythm to sinus. Usually, hyperthyroidism associated atrial fibrillation spontaneously reverts to sinus rhythm several weeks after achieving a euthyroid state. Control of thyroid function and heart rate is the goal of therapy for this type of atrial fibrillation.

Keywords: Hyperthyroidism - Arrhythmia - Atrial fibrillation - Familial atrial fibrillation - Cardioversion

Pediatric Cardiology
Volume 27, Number 6 / December, 2006, p. 772-774

Aortic stenosis: Standard of care

Aortic Stenosis: The Spectrum of Practice

O. Khalid1, D.M. Luxenberg1, C. Sable2, O. Benavidez3, T. Geva3, B. Hanna4 and R. Abdulla1
1) The University of Chicago, MC 4051, Chicago, IL 60637-1470, USA,

2) Children’s National Medical Center, Washington, DC, USA,

3) Children’s Hospital Boston, Boston, MA, USA, 4) Children Hospital of Philadelphia, Philadelphia, PA, USA

There is significant variation in practice patterns in managing congenital aortic valve stenosis. Review of medical literature reveals no significant information regarding the current practice methods in the treatment of a simple lesion such as aortic stenosis (AS). Therefore, this survey-based study was conducted in an attempt to better understand the uniformity or heterogeneity of practice in treating AS. A questionnaire was prepared to evaluate the style of management of AS. This survey was designed to assess the practice of follow-up visitations, type and frequency of investigative studies, pharmacological therapy, and exercise recommendations. Questions about therapeutic intervention included those of timing and type of intervention. Questionnaires were sent to all academic pediatric cardiology programs in the United States (48 program) and selected international programs from Europe, Asia, and Australasia (19 program). The total number of surveys sent out was 67, and the total number of respondents was 25 (37%), 15 (31%) from the United States and 9 (53%) from outside the United States. The definition of moderate AS varied among respondents. The range provided for mild AS was identified as that with a peak-to-peak pressure gradient of <> 50–60 mmHg, peak instantaneous Doppler gradient of > 64–80 mmHg, or mean Doppler gradient of > 45–64 mmHg. In assessing follow-up patterns, 84% of respondents recommended seeing patients with mild AS annually, the longest time of follow-up listed in the questionnaire, whereas 20% suggested follow-up every 6 months. There was no consensus among survey centers regarding follow-up of patients with moderate AS. For severe AS, 16% recommend immediate intervention, 16% arrange follow-up every 6 months, and 56 and 28% recommend follow-up in 3 and 1 month(s), respectively. In making the decision to proceed with biventricular versus univentricular repair in patients with AS in the neonatal period, many factors were considered. Ninety-two percent of respondents rely on mitral valve z score, 84% on aortic valve z score, 52% on left ventricle length, 48% on the presence of antegrade ascending aorta flow, and only 32% considered significant endocardial fibroelastosis as a factor. Rhodes score was used by 20% of respondents in decision making regarding the approach to management of this subset of AS. This study shows that there is consensus in the management of mild and severe forms of AS. As expected, disagreement is present in the definition, evaluation, and therapy of moderate aortic valve stenosis. There is a tendency for catheter intervention except in the presence of dysplastic aortic valve or moderate to severe aortic regurgitation. There is also disagreement regarding methods used to determine biventricular versus univentricular repair of a borderline hypoplastic left heart.

Key words: Aortic stenosis - Congenital heart disease - Standard of care - Survey

Pediatric Cardiology

Volume 27, Number 6 / December, 2006, p.661-669

Congestive Heart Failure: Depression

Depression Outcome in Inpatients With Congestive Heart Failure

Harold G. Koenig, MD

Background. High rates of depression are found among hospitalized patients with congestive heart failure. Little is known about the outcome of depression in these patients or factors that influence that outcome.

Methods. To assess baseline patient characteristics as predictors of time to remission in depressed inpatients with congestive heart failure, consecutive patients older than 50 years admitted with congestive heart failure were screened for major and minor depression using a structured clinical interview. Patients with minor depression were reevaluated at 6 and 12 weeks, and those with major depression at 6, 12, 18, and 24 weeks using the Longitudinal Interview Follow-up Evaluation.

Results. Of a total of 473 depressed patients, 404 (247 with minor depression and 157 with major depression) were identified and followed up. Patients with minor depression were followed up for an average of 11.3 weeks, during which 64.0% went into remission; those with major depression were followed up for 20.2 weeks, during which 47.8% went into remission. Baseline predictors of shorter time to remission for minor depression were less severe depression (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.92-0.98) and fewer comorbid illnesses (HR, 0.92; 95% CI, 0.87-0.98); patients who were younger and had better physical functioning and those not treated with antidepressants also tended to go into remission faster. For major depression, less severe depression was the primary predictor (HR, 0.92; 95% CI, 0.88-0.96), although patients who were younger, male, without a history of depression, and with fewer comorbid medical disorders also tended to go into remission faster. Fewer than 50% of patients with major depression received treatment, and only 12% had psychiatric consultations.

Conclusions. The outcome of minor depression may be more dependent on physical stressors, whereas major depression seems more affected by intrinsic vulnerability. Many patients with major depression were not treated, and few had psychiatric consultations.

http://archinte.ama-assn.org/cgi/content/abstract/166/9/991

Archives of Internal Medicine 2006; Vol. 166 No. 9, p.991-996
© 2006 American Medical Association.