Echocardiography in hypertrophic cardiomyopathy diagnosis, prognosis, and role in management

Hypertrophic cardiomyopathy (HCM) is diagnosed on the basis of left ventricular (LV) hypertrophy for which there is insufficient explanation (e.g. mild hypertension or mild aortic stenosis with marked hypertrophy). Echocardiography is an invaluable tool in the diagnosis and follow-up of patients with HCM. Echocardiographic assessment requires a comprehensive assessment in several imaging planes with careful attention to correct beam alignment in order to minimize errors in the measurement of LV wall thickness and appropriate identification of hypertrophy with an unusual distribution.

T2-weighted magnetic resonance imaging to assess myocardial oedema in ischaemic heart disease

Cardiovascular magnetic resonance imaging (CMR) is an established clinical tool for the identification of irreversible myocardial injury. More recently, experience with stress-perfusion CMR has increased sufficiently so that this now provides an accurate and reliable aid to clinical decision-making in patients with ischaemic heart disease. T2-weighted or "black blood" imaging is a technique used less frequently to examine the myocardium but one that is growing in stature. This article explains the rationale behind the technique and reviews recent data illustrating clinical and research scenarios in which the addition of T2-weighted sequences to standard cardiac scanning protocols might be warranted.

Is lowering phosphate exposure the key to preventing arterial stiffening with age?

Cardiovascular disease remains the leading cause of death world wide. Although atheroma is clearly important, the role of arteriosclerotic vascular disease is often overlooked. Arteriosclerosis causes increased arterial stiffness, with consequent systolic hypertension and left ventricular hypertrophy. Serum phosphate is increasingly being recognised as a cardiovascular risk factor and has been implicated in the development of arteriosclerosis and arterial calcification. Its determinants are unclear, but both diet and minor reductions in renal function may be important. Diets in affluent populations are high in phosphate because of increased consumption of animal protein and the use of phosphate-containing preservatives. This viewpoint suggests that the consumption of a phosphate-rich diet, exacerbated by the high prevalence of chronic kidney disease found in ageing populations, accelerates the development of arteriosclerosis. It is hypothesised that reducing phosphate intake will attenuate the progression of arterial stiffness with major beneficial effects upon cardiovascular mortality and morbidity.

Comparison of transthoracic echocardiography with harmonic imaging with transoesophageal echocardiography for the diagnosis of patent foramen ovale

The optimal diagnostic method for patent foramen ovale is currently unclear. This study compared bubble contrast second harmonic transthoracic (TTE) and transoesophageal echocardiography (TOE) on 87 consecutive patients referred for TOE for all indications. A right left shunt was diagnosed in 34 cases (39%), with TTE positive in 26 cases (sensitivity 76.5%), TOE positive in 27 cases (sensitivity 79.4%). Pitfalls of TTE included quality of echo and left sided valve lesions, and for TOE the ability to perform an adequate Valsalva manoeuvre. In conclusion, both tests have similar sensitivity and should be viewed as complementary modalities.

The treatment of coronary artery disease in patients with chronic kidney disease

Premature cardiovascular disease is the largest cause of mortality, and a major cause of morbidity, in patients with chronic kidney disease (CKD). Patients with end-stage kidney disease (ESKD) are at extreme risk, but cardiovascular event rates are increased even in early CKD. There is little controlled trial evidence on which to base treatment, as most therapeutic trials have excluded CKD patients. Current treatment strategies are therefore based upon small prospective studies or retrospective analyses of controlled trials and registry data. It is thus unclear whether CKD patients benefit from modern secondary preventive treatments in the same manner as patients with normal renal function. There is a need for randomized trials to identify effective drugs to prevent and treat coronary artery disease in CKD. Revascularization by CABG in CKD has been widely reported in registry data to provide better results than medical treatment or angioplasty. Recent angioplasty data in patients with CKD, however, show improving results, and the risks of CABG in CKD remain high. It is not clear which revascularization technique has a better outcome in patients 'equally suitable' on angiographic criteria for either procedure. The high rate of late adverse cardiovascular events after both CABG and angioplasty accentuates the need for effective secondary preventive therapy disease in these high-risk patients.

Monitoring the introduction of new drugs--Herceptin to cardiotoxicity

Trastuzumab (Herceptin), currently prescribed for metastatic breast cancer, has recently been shown to be effective as adjuvant therapy in early receptor 2 (HER2)-positive breast cancer. Cardiotoxicity is a serious adverse effect. A decrease in left ventricular ejection fraction (LVEF) occurs in as many as 27% of women treated with trastuzumab when combined with standard chemotherapy. The pathophysiology of this effect, which differs from the cardiotoxicity of anthracyclines, remains poorly understood. While overt heart failure is reversed with standard therapy, the longer-term consequences of asymptomatic declines in LVEF remain unknown. Monitoring 3-monthly for 5-10% changes in LVEF, the criteria for cessation of trastuzumab therapy in the clinical trials, is not possible for the population of women who might benefit from trastuzumab for early breast cancer. Extension of this therapy to an older and less fit population than those enrolled in the trials, with less rigorous cardiac screening, may result in significantly more cardiotoxicity.

Takayasu arteritis: Role of cardiovascular magnetic imaging

Takayasu arteritis (TA) is a primary arteritis of unknown cause that commonly affects the aorta and its main branches. Traditionally, X-ray contrast angiography has been the gold standard for diagnosis and review of this chronic disease but recent developments suggest that non-invasive imaging with multiplanar cardiovascular magnetic resonance imaging (CMR) and magnetic resonance angiography (MRA) have a number of advantages for use in routine care. This review utilises a series of cases referred for imaging at the Royal Brompton Hospital, London to illustrate these points of development.

Predicting late sudden death from ventricular arrhythmia in adults following surgical repair of tetralogy of Fallot

Tetralogy of Fallot was the first complex congenital cardiac defect to undergo open repair. The life expectancy and quality of life of those surviving surgery is now good, although late survival is compromised by the occurrence of sudden death. The emergence of successful methods for both the prevention of arrhythmias (including valve replacements and electrophysiological ablation) and the treatment of arrhythmias when they occur (including implantable defibrillators), has meant the identification of those at risk is of even greater importance. This paper reviews the predictive methods currently available to the practising physician caring for these increasingly common patients.

The -1185 A/G and -1051 G/A dimorphisms in the von Willebrand factor gene promoter and risk of myocardial infarction

Elevated plasma von Willebrand factor (VWF) levels are associated with coronary artery disease, although the precise mechanism for this is unclear. Recently, four linked dimorphisms in the VWF gene promoter were demonstrated to influence plasma VWF level. We conducted a case-control study of 525 acute myocardial infarction (MI) cases and 451 control subjects, all aged < or = 75 years, to assess the potential contribution of two of these dimorphisms (-1185 G/A and -1051 A/G) to the risk of MI. The frequency of the -1185A/-1051G haplotype, associated with elevated VWF levels, was similar in the case and control groups, yielding a haplotypic odds ratio for MI of 0.93 (95% CI 0.77, 1.12, P = 0.43), and there was no significant association between the -1185A/-1051G haplotype and the risk of MI in any subgroup analysed. We therefore conclude that possession of the -1185A/-1051G haplotype does not confer an increased risk for MI.

Novel platelet membrane glycoprotein VI dimorphism is a risk factor for myocardial infarction

BACKGROUND

Glycoprotein (GP) VI plays a crucial role in platelet activation and aggregation. We investigated whether polymorphic variation at the GP VI locus confers an increased risk of myocardial infarction (MI).

METHODS AND RESULTS

Coding and 5' and 3' non-coding regions of the GP VI gene were analyzed by polymerase chain reaction and conformation sensitive gel electrophoresis in 21 healthy subjects. Ten dimorphisms, 5 of which predicted amino acid substitutions (T13254C, A19871G, A21908G, A22630T, C22644A), were identified. Two core haplotypes involving 7 dimorphisms (C10781A and G10873A and all those predicting amino acid substitutions) were apparent. The contribution of the T13254C dimorphism, which predicted the substitution of serine 219 by proline, to risk of MI was assessed in 525 patients with acute MI and 474 controls, all aged <75 years. The allelic odds ratio (OR) for MI associated with the 13254C allele was 1.16 (95% CI, 0.91 to 1.46; P=0.23). Compared with corresponding control subgroups, the 13254CC genotype was more common among cases who were female (OR, 4.52; 95% CI, 1.23 to 16.64; P=0.029), nonsmokers (OR, 2.50; 95% CI, 0.98 to 6.38; P=0.048), aged >/=60 years (OR, 6.48; 95% CI, 1.47 to 28.45; P=0.009) or carried the beta-fibrinogen -148T allele associated with increased fibrinogen levels (OR, 10.49; 95% CI, 1.32 to 83.42; P=0.02). In logistic regression analysis that took other cardiovascular risk factors into account, the interactions of GP VI genotype with age (P=0.005) and beta-fibrinogen genotype (P=0.035) remained significant.

CONCLUSIONS

The GP VI 13254CC genotype increases the risk of MI, particularly in older individuals, and the interaction of the GP VI 13254C allele with other candidate risk alleles may accentuate this risk.

Analysis of the postulated interaction between the angiotensin II sub-type 1 receptor gene A1166C polymorphism and the insertion/deletion polymorphism of the angiotensin converting enzyme gene on risk of myocardial infarction

A synergistic interaction between the insertion/deletion (I/D) polymorphism within the angiotensin-converting enzyme (ACE) gene and an A/C transversion at nucleotide position 1166 within the angiotensin II sub-type 1 receptor (AT1R) gene on risk of myocardial infarction has been reported. The risk associated with the ACE DD genotype increased with the number of AT1R C alleles present. To investigate this further, ACE I/D and AT1R A1166C genotypes were determined in 541 cases recruited at the time of infarction and 507 population-based controls. There was no difference in either the genotype distribution or allele frequencies between cases and controls for either the ACE polymorphism (P=0.48 and 0.35 respectively) or the AT1R polymorphism (P=0.35 and 0.21 respectively). Odds ratios for risk of MI associated with the ACE DD and AT1R CC genotypes were 1.09 (95% CI, 0.82-1.45) and 1.06 (0.67-1.68) respectively. 3.1% of cases versus 3.6% of controls were homozygous for both the D and C alleles (P=0.71). There was no increase in risk associated with the DD genotype in the presence of either one or two AT1R C alleles in the whole cohorts (OR 0.99, 95% CI 0.65-1.51 and 0.76, 95% CI 0.30-1.88, respectively) nor in sub-groups defined by specific risk factors. In conclusion, no evidence was found to support any interaction between the ACE gene I/D polymorphism and the ATIR gene A1166C transversion in determining the risk of myocardial infarction in the population studied.

Low-dose transdermal testosterone therapy improves angina threshold in men with chronic stable angina: A randomized, double-blind, placebo-controlled study

BACKGROUND

Experimental studies suggest that androgens induce coronary vasodilatation. We performed this pilot project to examine the clinical effects of long-term low-dose androgens in men with angina.

METHODS AND RESULTS

Forty-six men with stable angina completed a 2-week, single-blind placebo run-in, followed by double-blind randomization to 5 mg testosterone daily by transdermal patch or matching placebo for 12 weeks, in addition to their current medication. Time to 1-mm ST-segment depression on treadmill exercise testing and hormone levels were measured and quality of life was assessed by SF-36 at baseline and after 4 and 12 weeks of treatment. Active treatment resulted in a 2-fold increase in androgen levels and an increase in time to 1-mm ST-segment depression from (mean+/-SEM) 309+/-27 seconds at baseline to 343+/-26 seconds after 4 weeks and to 361+/-22 seconds after 12 weeks. This change was statistically significant compared with that seen in the placebo group (from 266+/-25 seconds at baseline to 284+/-23 seconds after 4 weeks and to 292+/-24 seconds after 12 weeks; P:=0.02 between the 2 groups by ANCOVA). The magnitude of the response was greater in those with lower baseline levels of bioavailable testosterone (r=-0. 455, P:<0.05). There were no significant changes in prostate specific antigen, hemoglobin, lipids, or coagulation profiles during the study. There were significant improvements in pain perception (P:=0.026) and role limitation resulting from physical problems (P:=0.024) in the testosterone-treated group.

CONCLUSIONS

Low-dose supplemental testosterone treatment in men with chronic stable angina reduces exercise-induced myocardial ischemia.

Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms

AIMS

High androgen levels are presumed by many to explain the male predisposition to coronary artery disease. However, natural androgens inhibit male atherosclerosis(1). Our aim was to determine whether levels of androgens differ between men with and without coronary artery disease.

METHODS AND RESULTS

Ninety male subjects (60 with positive, and 30 with negative coronary angiograms) were recruited. Early morning, fasting blood samples were taken from each patient and free, total and bioavailable testosterone, sex hormone binding globulin, oestradiol, and lipids were measured. Bioavailable testosterone was assayed using a modified technique. Free androgen index was calculated. Men with coronary artery disease had significantly lower levels of free testosterone (mean (standard deviation)); 47.95 (13.77) vs 59.87 (26. 05) pmol. l(-1), P=0.027), bioavailable testosterone; 2.55 (0.77) vs 3.26 (1.18) nmol. l(-1), P=0.005 and free androgen index; 37.8 (10. 4) vs 48.47 (18.3), P=0.005, than controls. After controlling for differences in age and body mass index the differences in free androgen index and bioavailable testosterone remained statistically significant (P=0.008 and P=0.013, respectively).

CONCLUSION

Men with coronary artery disease have significantly lower levels of androgens than normal controls, challenging the preconception that physiologically high levels of androgens in men account for their increased relative risk for coronary artery disease.

Sonography in the diagnosis of rhabdomyolysis

This case report describes the use of musculoskeletal sonography in the diagnosis of rhabdomyolysis. The case involved an episode of severe muscle lysis following a heroin overdose in an addict who lay comatose for an uncertain period. Sonography revealed multiple hyperechoic areas within the muscles examined, consistent with a recent injury. The clinical diagnosis of rhabdomyolysis may be difficult but is important in view of the attendant danger of acute renal failure, and sonography was instrumental in the diagnosis in this case.

Human vascular reactivity and polymorphisms of the angiotensin-converting enzyme and the angiotensin type 1 receptor genes

The D allele of the insertion (I)/deletion (D) polymorphism in the angiotensin-converting enzyme (ACE) gene and the C allele of the A1166-C polymorphism in the angiotensin II type 1 receptor (AGT1R) gene have been associated with altered vascular structure and with an increased risk of myocardial infarction. The aim of this study was to determine whether differences in vascular function could be demonstrated to link the previously described changes in structure and the disease outcome. 70 subjects were recruited at random from patients undergoing colonic resection, resistance arteries were excised and were mounted in a small vessel wire myograph. Vasomotor responses to potassium chloride, noradrenaline, prostaglandin F(2alpha), angiotensin I, angiotensin II, acetylcholine and substance P were performed in 30 subjects. Genotype was established in a blinded fashion after completion of myography. To exclude the possibility of masking of genetic influence by non-ACE conversion of angiotensin I, vasomotor responses were then performed to proline(10)-angiotensin I in a further 30 subjects and to angiotensin I in the presence of chymostatin in a further 10 subjects. No significant effect of the I/D polymorphism of the ACE gene was seen on vasomotor function. The C allele of the AGT1R gene was associated with an increase in sensitivity to prostaglandin F(2alpha) but not with alteration to the other vasoactive agents studied. The I/D ACE and A1166-C AGT1 receptor polymorphism do not appear to result in differences in vasomotor function in isolated human mesenteric resistance arterioles in subjects without evidence of underlying hypertensive or cardiovascular disease.

The GPIa C807T dimorphism associated with platelet collagen receptor density is not a risk factor for myocardial infarction

The platelet collagen receptor, GPIa/IIa, is an important mediator of platelet adhesion to fibrillar collagens at sites of vascular injury. Recently, a dimorphism at nucleotide 807 of the GPIa cDNA (TTC/TTT in codon 224) was shown to be associated with variation in GPIa/IIa receptor density on the platelet surface. We conducted a case-control study to determine if the 807T allele, linked with increased GPIa/IIa density, contributed to risk of myocardial infarction (MI). DNA from 546 acute MI cases and 507 controls, all aged <75 years, was genotyped for the C807T dimorphism using the TaqManTM system of allelic discrimination. The allelic odds ratio (OR) for MI in the complete cohort was 0.88 (95% CI 0.74-1.05, P = 0.17), indicating that the 807T allele was not associated with an increased risk of MI. There was also no increased risk of MI associated with the homozygous 807TT (P = 0.22) or heterozygous 807CT (P = 0.24) genotypes or for carriers of the 807T allele in any cohort subgroup analysed. We conclude that the GPIa 807T allele is not a risk factor for MI in our population either alone or in combination with other major cardiovascular risk factors.

An open label, randomised, crossover study comparing sotalol and atenolol in the treatment of symptomatic paroxysmal atrial fibrillation

OBJECTIVE

To compare sotalol and atenolol in the treatment of symptomatic paroxysmal atrial fibrillation.

DESIGN

Prospective, randomised, open label, crossover study.

SETTING

University hospital.

PATIENTS

47 subjects aged over 50 years were recruited from the hospital outpatient department following ECG documentation of paroxysmal atrial fibrillation that coincided with symptoms. Six patients withdrew and 41 completed the trial.

INTERVENTIONS

Patients were randomised to one month's treatment with sotalol 80 mg twice daily or atenolol 50 mg once daily. Treatment arms were then crossed over. Patients underwent 72 hour Holter monitoring before randomisation and repeat studies were carried out at the end of both treatment periods. Symptom assessments were completed using linear analogue scales and the Nottingham health profile.

MAIN OUTCOME MEASURE

Frequency of paroxysmal atrial fibrillation; secondary outcome measures included average and total duration of paroxysmal atrial fibrillation, total ectopic count, and symptom assessments.

RESULTS

A reduction in the number and duration of episodes of paroxysmal atrial fibrillation was noted following treatment with sotalol and atenolol. There was no difference in frequency of paroxysmal atrial fibrillation during treatment with sotalol or atenolol (median difference 0; 95% confidence interval (CI) 0 to 1; p = 0.47). There was no difference in total duration of paroxysmal atrial fibrillation (median difference 0 min; 95% CI -1 to 2; p = 0. 51) or in average duration (median difference 0 min; 95% CI 0 to 1; p = 0.31). No difference was found in total ectopic count between sotalol and atenolol (median difference -123; 95% CI -362 to 135; p = 0.14). Treatments were equally tolerated with no difference in linear analogue scores for symptoms of paroxysmal atrial fibrillation (median difference -5; 95% CI -20 to 5; p = 0.26) or in all categories of the Nottingham health profile.

CONCLUSIONS

No difference was found in terms of ECG or symptomatic control of paroxysmal atrial fibrillation between prescribing sotalol 80 mg twice daily and atenolol 50 mg once daily. There was an improvement in paroxysmal atrial fibrillation from baseline following treatment with either sotalol or atenolol.

The prothrombin 20210A allele and its association with myocardial infarction

The relationship between the prothrombin (PT) 20210A allele and arterial disease is controversial. We conducted a case-control study to assess its contribution to risk of myocardial infarction (MI). Five hundred and thirty-nine acute MI patients and 498 control subjects aged <75 years were studied. Two percent of cases carried the PT20210A allele compared to 2.8% of controls. The odds ratio for MI was 0.72 (95% CI 0.32-1.60) indicating that the PT20210A allele confers no increased risk for MI. Subgroup analysis showed no association between the PT20210A allele and either premature MI or MI in females. We conclude the PT20210A allele is not a risk factor for MI and suggest that discrepancies in studies relating the PT20210A allele to MI may be due to difficulties in estimating its low allelic frequency in the general population and thus random differences in the observed frequencies in the control populations studied.

Lumbar puncture in subarachnoid haemorrhage: a necessary evil?

A 70-year-old lady was admitted following the sudden onset of a severe, throbbing headache 7 days previously. The headache was occipital in location, with radiation to the back of the neck and both shoulders. The patient had vomited twice at the onset of the pain but, although initially severe, the headache had gradually resolved without further complication. The patient had a history of hypertension, controlled on bendrofluazide 2.5 mg once daily. A mastectomy had been performed in 1992 for carcinoma of the breast.

Clinical examination revealed a sinus tachycardia 120 beats per minute and systolic hypertension 170/80 mmHg. Examination was otherwise unremarkable. Investigations included a normal full blood count, liver function tests, bone profile, random glucose, and electrocardiogram. Computed tomography scan of the head was normal. The only abnormality was the finding of a low sodium 132 mmol/litre, attributed to the diuretic, and serum electrolytes were otherwise unremarkable. The patient was discharged as she was asymptomatic and the sinus tachycardia had settled.

Unfortunately, the patient was re-admitted the following day complaining of numbness on the right side of the face, together with low back pain. Clinical examination revealed mild cerebellar ataxia. A lumbar puncture was performed with the isolated finding of xanthochromia. A cell count was not performed on the cerebrospinal fluid (CSF). Subsequent cerebral angiography documented a right posterior communicating artery aneurysm, which was clipped 3 days later. The patient was discharged 10 days later with no neurological deficit.

A 37-year-old lady was admitted following the sudden onset of a severe occipital headache 5 days previously. The headache had failed to resolve on simple analgesics. She had vomited twice and had developed mild photophobia. There were no apparent precipitants for the pain and there was no other relevant history.

Clinical examination was unremarkable, except for the finding of mild neck stiffness and photophobia. The patient had an elevated white cell count (14.9 × 109/litre) but full blood count, serum electrolytes and glucose were otherwise normal. The initial report of the computed tomography scan of the head was normal, although a later review raised the possibility of hydrocephalus.

A lumbar puncture was performed with the finding of xanthochromia, CSF red blood cells 25 000 and CSF white cell count 200 (90% polymorphs). No organisms were seen. CSF opening pressure was 12 cm. The patient was transferred to the tertiary centre and she underwent cerebral angiography which documented a left posterior cerebral artery aneurysm. This was embolized at surgery 5 days later. Postoperative recovery was complicated by communicating hydrocephalus with a CSF pressure of 40 cm, which responded well to lumbar puncture. The patient was discharged 10 days later with no neurological deficit.

A 31-year-old lady was admitted following the sudden onset of headache 4 hours before admission. The headache was generalized, sharp in nature and associated with two episodes of vomiting. There was no neck stiffness and no photophobia. There were no other relevant features on the history.

Clinical examination revealed a stable pulse rate of 72 beats per minute, blood pressure 130/76 mmHg and mild neck stiffness but no other focal deficit. The patient had an elevated white cell count (16.4 x 109/litre) but full blood count, serum electrolytes, and glucose were otherwise normal. Computed tomography scan of the head was normal. Lumbar puncture was performed, with the finding of 101 000 red cells, 125 white cells (60% polymorphonuclear leucocytes; 40% lymphocytes) but no xanthochromia. The patient was transferred to the tertiary neurosurgical centre, where she underwent cerebral angiography. This documented an aneurysm arising from the left internal carotid artery, with a proximal daughter aneurysm. These were clipped at surgery and the patient was discharged 10 days later with no neurological deficit.

Selective treatment for heart failure: the future beckons?

Myocardial failure results from a variety of insults yet treatments have been given in a nonselective way. The benefits of treatments on symptoms are not related to etiology, but there is increasing evidence that prognosis is. Whenever the prognostic benefits of treatments have been classified according to etiology, patients with myocardial damage without concomitant ischemic heart disease fare better. In this paper, we present and evaluate the data on prognosis and discuss the possible reasons behind these differences. These differences are important because they will help to inform patients and physicians about prognosis based on the underlying cause of myocardial damage. In the future, treatment may be more successful if it is targeted to patients according to the cause of heart failure.

Response of normoxic pulmonary arteries of the rat in the resting and contracted state to NO synthase blockade

1. The pulmonary vasculature is normally in a low resting state of tone. It has been hypothesized that this basal tone is actively maintained by the continuous release of a vasodilator in the resting state. However, evidence for basal release of nitric oxide (NO) is inconclusive. 2. We studied the release of NO in arteries from the pulmonary circulation of male Wistar-Kyoto rats by examining the effects of the L-arginine analogue NG-nitro-L-arginine methyl ester (L-NAME) on resting pulmonary arteries and on vessels pre-contracted with prostaglandin F2(alpha) (PGF2 alpha). 3. Rats (n = 21) were killed by an overdose with pentobarbitone. Pulmonary arteries were dissected (mean internal diameter 459 +/- 11 microns) and mounted in a small vessel wire myograph. Resting tensions were to set to stimulate transmural pressures of 17.5 mmHg. 4. L-NAME (100 microM) was found to produce a contraction of 0.64 +/- 0.09 mN mm-1 in resting pulmonary arteries when added alone to the myograph bath. This contraction was not produced following removal of the endothelium. Vessel contraction to PGF(2 alpha) (100 microM) was found to be significantly greater when carried out in the presence of L-NAME (100 microM) -1.37 +/- 0.15 mN mm-1 compared with 1.96 +/- 0.17 mN mm-1. Dilation following acetylcholine (ACh) (1 microM) was abolished in the presence of L-NAME (100 microM). 5. Rat pulmonary artery contraction in response to the addition of L-NAME and the absence of contraction upon removal of the endothelium provides supportive evidence of the active release of nitric oxide for the maintenance of resting tone.

Prognostic implications of qualitative assessment of left ventricular function compared to simple routine quantitative echocardiography

OBJECTIVE

To compare the prognostic value of qualitative estimates of left ventricular function with that of routine simple quantitative indices used in echocardiography.

DESIGN

Retrospective follow up study.

SETTING

University hospital.

PATIENTS

The records of 2,964 patients who had undergone echocardiography and who could be traced on the family health services register were examined; 919 cases were included in the study, and a further 458 were used to validate the statistical models for prognostic assessment. There were 928 exclusions on the basis of referral for or diagnosis of alternative conditions, and 659 because of incomplete collection of the qualitative and quantitative data used in the study.

MAIN OUTCOME MEASURE

Survival over the study period.

RESULTS

A qualitative "eyeball" estimate of left ventricular function was of prognostic significance (relative risk of poor v good, 2.248; P << 0.001; 95% confidence interval 1.620 to 3.119). None of the quantitative echocardiographic indices was of independent prognostic significance when all variables were tested simultaneously in the regression model.

CONCLUSIONS

A qualitative echocardiographic estimate of left ventricular dysfunction is of prognostic value, supporting the view of many cardiologists who use their overall impression of left ventricular function at echocardiography as the basis for treatment decisions.

How important is family history in ischaemic heart disease?

A positive family history is an established risk factor for ischaemic heart disease, but the size of the contribution relative to classical risks is open to debate. The literature suggests that inherited factors are important in the development of premature ischaemic heart disease, but decline in importance with age. A polymorphism in the angiotensin-converting-enzyme gene was the first new genetic factor thought to contribute independently and significantly to cardiovascular risk. However, more recent large prospective studies have indicated that its contribution is smaller than was originally thought. Interventions should continue to be targeted at the reduction of important environmental factors, such as smoking cigarettes.