The skinny on wide QRS complexes

The presence of widened QRS complexes in a life insurance applicant's electrocardiogram may be due to such things as an intraventricular conduction defect, preexcitation syndrome, left ventricular hypertrophy, ventricular pacing, hyperkalemia and a ventricular rhythm. Clinical information and basic electrocardiogram interpretation techniques can usually narrow the differential diagnosis. Risk assessment of intraventricular conduction defects requires identification of typical electrocardiographic patterns followed by a careful search for additional electrocardiographic features, which may indicate the presence of more extensive conducting system disease and/or coexisting disease affecting the myocardium.     

Matters of the athletic heart

Frequently an underwriter or medical director will question whether an increase in left ventricular mass represents pathologic left ventricular hypertrophy (LVH) or physiologic changes related to exercise. The LVH condition reflects end-organ damage related to abnormal hemodynamic stresses and confers an increased morbidity and mortality risk. When left ventricular mass is increased because of exercise, measured changes represent a normal, healthy cardiovascular system responding to the demands of that exercise. This article summarizes medical findings that distinguish pathologic LVH from an "athletic heart."     

Poor R-wave progression

Poor R-wave progression is a common ECG pattern, which is often inconclusively interpreted by medical directors. Although this ECG pattern is commonly attributed to anterior myocardial infarction, it may also be caused by left bundle branch block, Wolff-Parkinson-White syndrome, right and left ventricular hypertrophy as well as by faulty ECG recording technique. Failure to make a definitive interpretation of this pattern may result in a delay or loss of business.     

Diastolic dysfunction of the left ventricle. A review of the physiology, causes, diagnosis, treatment and implications

Diastolic dysfunction of the left ventricle frequently occurs in people with left ventricular hypertrophy and coronary artery disease. It is a common cause of congestive heart failure, especially in the elderly. The mechanism of diastolic dysfunction, its causes, diagnosis and treatment, are reviewed. These are important factors to a Medical Director who must assess the results of non-invasive studies. Alerted by the possibility of diastolic dysfunction, the Medical Director can be more sensitive to other signs and symptoms that may represent early signs of congestive heart failure or ischemia.     

Tall R wave in lead V1

Tall R waves in lead V1 present the life insurance company medical director with a diagnostic dilemma. This ECG pattern may be present in applicants with right bundle branch block, right ventricular hypertrophy, Wolff-Parkinson-White syndrome, posterior myocardial infarction, hypertrophic cardiomyopathy, muscular dystrophy, dextrocardia, misplaced precordial leads, as well as in normal individuals. This ECG case study discusses the ECG features involved in the differential diagnosis.     

Diastolic dysfunction

Diastolic dysfunction of the heart is characterized by normal left ventricular contractility and normal ejection fraction, however ventricular relaxation is impaired. In systolic dysfunction, ventricular contractility and ejection fraction are reduced, in addition to impaired relaxation. The prevalence of diastolic dysfunction is increased in the elderly, especially those who have had inadequately treated hypertension. Both diastolic and systolic dysfunction may result in similar clinical signs and symptoms. Therefore, echocardiography is needed to make the distinction. Left atrial (LA) enlargement, assessed by left atrial volume indexed to body surface area, appears to be the best measure to assess diastolic function. LA enlargement is likely when indexed LA volume is > or = 34-40 mL/m2. B-type natriuretic protein appears to be useful for the diagnosis, assessment and prognosis of heart failure, but it does not distinguish between the two types of dysfunctions. Several drug treatments that have effects on the mechanism of diastolic dysfunction are under investigation.     

Utilizing NT-proBNP in the selection of risks for life insurance

Brain natriuretic peptide (BNP) is a counter-regulatory hormone produced mainly by ventricular myocardium. Early research studies were performed to ascertain its value in the diagnosis of congestive heart failure in acute care settings. Subsequent studies have explored its utility in screening for asymptomatic left ventricular dysfunction in the community, determining prognosis in coronary artery disease, appropriate timing of surgery in valve disorders, and in evaluating many other cardiac diseases. This review summarizes the current status of medical literature, introduces a new test to the insurance industry.     

LVH: consequences associated with cardiac remodeling

With increased hemodynamic stress, the heart must adjust to meet the greater demands placed upon it. This adjustment frequently involves an alteration or remodeling in its structure or geometry, which augments its performance and helps to maintain adequate function under changing conditions. One of the most important forms of remodeling that the heart may undergo is an increase in muscle mass in response to a pressure or volume overload or myocardial injury. This increase in muscle mass is known as left ventricular hypertrophy (LVH). LVH is of great importance from a risk selection perspective for two reasons: it is common, and it is associated with a significant increase in both morbidity and mortality risk. Thus, it is critical that both underwriters and medical directors be aware of this form of remodeling, its causes, diagnosis and consequences.     

Short PR interval

A short PR interval may be associated with an otherwise normal electrocardiogram or a myriad of bizarre electrocardiographic abnormalities. Clinically, the individual may be asymptomatic or experience a variety of complex arrhythmias, which may be disabling and rarely cause sudden death. In life insurance applicants, it is important to recognize these abnormalities and to assess their risk appropriately.     

Right atrial abnormality

Occasionally, a prominent P wave is encountered in a life insurance applicant's electrocardiogram. Prominent P waves may be normal variants or alert the medical director to prognostically significant structural heart or pulmonary disease. This case study reviews the commonly used criteria for the ECG pattern of right atrial abnormality and some of the pitfalls associated with its use.     

Q waves--does depth matter?

Deep narrow Q waves in an electrocardiogram may be significant and should suggest several possible diagnoses. By considering the leads where they are observed, the presence of additional ECG abnormalities, the applicant's age and any relevant clinical information, one can considerably narrow the diagnostic possibilities.     

The challenge of inferior Q waves

The presence of unexpected Q waves in an applicant's electrocardiogram poses a diagnostic dilemma for the medical director. On the one hand, the Q waves may be the remnants of a previously unsuspected "silent" myocardial infarction. Conversely, unexpected Q waves may represent a normal or positional variant, or an important noncoronary type of heart disease. This case study illustrates some of the pitfalls in interpreting applicants' electrocardiograms containing Q waves in the inferior leads.     

Myocardial infarction or technical artifact?

Misplacement of recording electrodes can generate misleading patterns on the standard 12-lead electrocardiogram (ECG). Some lead placement errors are easily recognizable, others are more difficult to detect and can be quite important in risk selection because the resulting changes in ECG morphology can mimic other conditions such as myocardial infarction. Therefore, identification of incorrectly performed ECGs is an important task for the medical director.     

Low amplitude P, QRS and T wave pattern in lead I--the "isoelectric lead I sign"

An applicant's electrocardiogram contains a low amplitude P, QRS and T wave pattern in lead I. The diagnostic and prognostic implications of this ECG pattern are discussed.     

Bradycardia in a former professional athlete

A mild bradycardia is noted in the electrocardiogram of a former professional hockey player applying for life insurance. The electrocardiographic differential diagnosis and prognostic implications are discussed.     

"Flat line" in a limb lead

A life insurance applicant's electrocardiogram shows a flat line in one of the standard leads and new Q waves in the inferior leads. The clinical and risk assessment implications are reviewed.     

Positive computer-generated exercise electrocardiogram

The use of computerized averaging of the electrocardiogram (ECG) during stress testing has facilitated the removal of motion artifacts and baseline shifts. However, this process can introduce errors, which may not be appreciated by medical directors. Such errors can lead to significant ST depression in the absence of coronary artery disease. Such false-positive tests may lead to anxiety in the applicant, delays in accepting the application and unnecessary additional testing. This case study illustrates a common pitfall associated with using only a computer-generated exercise ECG for risk assessment of a life insurance applicant.     

The Brugada syndrome--an electrocardiogram with important mortality implications

The electrocardiogram (ECG) is a valuable screening tool for increased risk in underwriting life insurance applicants. This article discusses a recently described ECG pattern associated with a high risk of sudden unexpected death.     

Early repolarization ECG pattern--still a benign finding?

A life insurance applicant with an early repolarization pattern on his electrocardiogram (ECG) previously assessed as a standard risk, wishes to increase the amount of his coverage. The risk assessment implications of recent studies of early repolarization ECG patterns are reviewed.     

Nonsustained wide QRS tachycardia during an exercise ECG stress test

The evaluation of a nonsustained wide QRS tachycardia in a life insurance applicant's exercise test presents a special challenge to the medical director because of the unpredictable and potentially lethal nature of these arrhythmias. Ventricular tachycardia accounts for up to 80% of wide QRS tachycardias in unselected populations and more than 95% of cases with a prior myocardial infarction. Malignant ventricular arrhythmias usually occur in the presence of significant structural heart disease. In this setting, ventricular arrhythmias carry a high risk of sudden cardiac death. Less commonly, ventricular tachycardia occurs in hearts that appear normal. In many such cases, however, the heart is in fact not normal, but rather has less visible abnormalities including derangements of cardiac ion channels or structural proteins. In these individuals, ventricular arrhythmias also carry a high risk of sudden cardiac death. There are, however, some ventricular tachycardia syndromes which occur in normal hearts that have a more benign prognosis.