The COVID-19 HL School Principal Survey (Wales) linked to routinely collected anonymised health data

Background

Evidence before the pandemic suggests that school headteachers report high work-related stress and psychological/physical burden compared to other professional groups (1). There is an evidence gap exploring the effects of the COVID-19 pandemic on senior leaders in schools who have experienced high demands as a result of COVID-19. This is important because in the UK, teacher retention is policy priority.

Methods

The COVID-19 HL: School Leadership Survey aimed to explore the burden and stress that school leaders in Wales, UK experienced during COVID-19, part of a global study with the COVID-HL network (3). 172 school leaders (62% female) from 130 primary (age 3-11) and 30 secondary schools (age 11-16) completed an online survey between July-Nov 2021, exploring topics such as work-related stress and mental health. A unique aspect is the use of data linkage using the SAIL (Secure Anonymised Information Linkage) Databank. SAIL is data repository containing individual-level, anonymised population-scale data for Wales.

Results

Initial descriptive findings show 54% of senior leaders have depression (WHO-5), and lower wellbeing scores compared to other UK professions. 83% report moderate-high perceived stress (Perceived Stress Scale) and physical (38%) and mental (57%) work exhaustion. The next stage of this study is to perform data linkage of survey responses to health records and administrative data. Logistic regression analyses will examine wellbeing and work-related stress with outcomes including mental health (e.g. anxiety/depression) diagnosis and time off work.

Conclusions

Preliminary results show high levels of stress, exhaustion and low wellbeing amongst school leaders in Wales. The next part of this study will examine this in greater detail using data linkage of routine records. Data linkage allows this sample to be extrapolated to population level to theorise work-related stress for all school leaders in Wales.

Determining the acceptability of testing contacts of confirmed COVID-19 cases to improve secondary case ascertainment

Background

UK asymptomatic contacts of confirmed COVID-19 cases are not routinely tested for SARS-CoV-2. Testing contacts may improve case ascertainment and reduce onward transmission. This study investigated the acceptability of SARS-CoV-2 testing among contacts of confirmed cases as an integral part of the contact-tracing process.

Methods

A cross-sectional descriptive survey of case contacts was conducted in the UK. All contacts who completed a telephone call with the NHS Test and Trace Agile Lighthouse team were eligible for inclusion and were offered a molecular test. Consenting participants were sent a self-swab kit.

Results

Of the 1523 individuals contacted, 602 (39.5%) accepted the test offer. Of the 240 (39.9%) samples returned for testing, 16.3% tested polymerase chain reaction-positive for SARS-CoV-2.

Most individuals who declined with a reason (638/905; 70.5%) reported they had already taken or booked a SARS-CoV-2 test, or were part of a testing programme. Matched laboratory records confirmed 73.1% of those who declined were tested by another route.

Conclusions

Most case contacts were tested, either through arranging a test by themselves or by accepting the study offer. Results demonstrate high acceptability, with substantial test positivity, indicating that there is public health benefit in offering tests to contacts as a routine part of the contact-tracing process.

[The collagen of the restenosis post angioplasty with stent: Is its origin in intima or adventitia?]

BACKGROUND

Restenosis post stenting is due to the deposit of extracellular matrix, mainly collagen in the neointima. Controversy exists regarding if collagen is generated locally or by immigration from the adventitia.

AIM

To study the fibrocellular response after stent implantation in rabbit iliac arteries. To observe, by immunohistochemistry and in situ hybridization, if collagen type I mRNA is expressed in the neointima, in the media or in the adventitia.

MATERIAL AND METHODS

Thirty eight white rabbits (New Zealand) of 4 kg received an hypercholesterolemic diet during 1 month. After this period, in all but 6 of them, an angioplasty with stent implantation was performed via right carotid artery in both iliac arteries, using a 1:1.3 relationship regarding the reference vessel. Angiograms were performed at day 0, 4, 21, and 40, followed by paraffin fixation of the injured segments, immunohistochemistry for alpha-actin and in situ hybridization to detect procollagen type I (alpha 1R1) mRNA.

RESULTS

No hybridization was observed in non injured arteries or at day 0 (n = 6). Expression of alpha 1R1 mRNA was observed in the neointima starting at day 4 after stenting (n = 8). At day 21 (n = 8) hybridization of procollagen type I was not only observed in the neointima, but also in the media, which became equally intense in both areas. At day 40 (n = 6) hybridization was observed similarly in the media and adventitia.

CONCLUSIONS

In this model, hybridization of procollagen type I started in the neointima, then involved the media and finally the adventitia. This finding might be useful for designing therapies to be delivered locally at the end of an angioplasty to prevent collagen deposition in the neointima.

Predictors of radial artery patency for coronary bypass operations

BACKGROUND

Few data exist regarding angiographic predictors of radial artery patency for coronary bypass grafting, and the benefit of calcium antagonists is not clear.

METHODS

One hundred fifteen patients were studied who had myocardial revascularization with the radial artery plus internal mammary and vein grafts with 3.5 +/- 1.1 grafts per patient. Sixty-three patients received diltiazem and 52 patients did not. Base line and follow-up angiographies were analyzed 1 year postoperatively in 50 of these patients with a quantitative computerized method.

RESULTS

One hundred fourteen patients survived and were followed for 30.1 +/- 12.6 months. Patency for mammary grafts was 100%, for radial grafts it was 80%, and for saphenous vein grafts it was 68%. Patent radial artery grafts had significantly greater degree of stenosis in the native vessels than occluded grafts (73% +/- 14% vs 40% +/- 24%), (p = 0.0007; confidence interval = 95%). Radial artery patency increased to 92% when arteries with 70% or more stenosis were considered. No differences were observed for clinical and angiographic end points in the patients that received diltiazem compared with the rest who had not.

CONCLUSIONS

The degree of stenosis in the native coronary artery significantly influences the patency rate of radial artery grafts, independent of diltiazem.

[Treatment of advanced heart failure by heart transplantation]

BACKGROUND

Heart transplantation currently provides the most effective treatment for advanced heart failure. However, medical therapy for this condition has also improved, heart donors are scarce and the cost of the procedure is high. Therefore the indications and management of these patients need reevaluation.

AIM

To analyze the results of 24 patients submitted to heart transplantation for end-stage heart failure needing repeated hospitalizations and i.v. inotropes for compensation.

PATIENTS AND METHODS

The group was comprised by 21 men and 3 women with a mean age of 36.8 years, mean left ventricular ejection fraction 19 +/- 4.5%, mean systolic pulmonary artery pressure 48 +/- 13 mmHg (24-70) and mean pulmonary vascular resistance 2.6 Wood Units (1-5). Fourteen patients (58%) had a previous median sternotomy. Immunosuppression did not include induction therapy and steroids were discontinued early.

RESULTS

Operative mortality was 4% at 30 days. Actuarial survival at one year was 90% and at 5 years 72%. Freedom from rejection at one year was 76% and at 5 years 50%. Freedom from infection was 70% at one year and 56.5% at five years. All patients with more than 3 months of follow-up were in functional class I.

CONCLUSIONS

These results justify the proposed modifications for transplantation protocols.

[D/D genotype of the gene for angiotensin converting enzyme as a risk factor for post-stent coronary restenosis]

INTRODUCTION

Although intracoronary stenting has decreased restenosis rate compared to percutaneous balloon angioplasty, still a high number of patients develop in-stent restenosis, which is an entity primarily due to tissue proliferation. Experimental studies have indicated that the renin-angiotensin system is involved in neointimal hyperplasia. Plasma and cellular levels of ACE are associated with an I/D polymorphism in the ACE gene. Indeed, DD subjects have the higher ACE levels. The purpose of this study was to explore the possibility that the I/D polymorphism might be related with in-stent restenosis.

METHODS

We studied the ACE polymorphism in 48 consecutive patients who underwent successful implantation of an elective coronary stent in native coronary vessels and had a 6 month angiographic follow up. Restenosis (50% of the reference vessel) was observed in 23/48 patients. Patients with or without restenosis did not differ in demographic or clinical variables like diabetes, plasma cholesterol levels or in quantitative angiographic parameters such as vessel reference size or minimal lumen diameter after stent implantation.

RESULTS

I/D polymorphism was distributed as follows: 22.9% of the patients were D/D; 14.5% were I/I and 62.5% of the patients were heterozygous I/D. The presence of restenosis was strongly related with the I/D polymorphism: 81.8% of the patients with D/D genotype had restenosis, compared with 40.0% of I/D patients and only 14.2% of the I/I patients (chi 2 p < 0.01).

CONCLUSIONS

In this limited cohort, homocygous D/D of the ACE gene was significantly associated with in-stent restenosis, whereas restenosis was infrequent in patients with the I/I genotype.

[Unstable angina: immediate and one-year results of transluminal coronary angioplasty treatment]

BACKGROUND

Unstable angina is characterized by angina at rest, angina of recent onset or accelerating angina. It is caused by a fissure or ulceration of an atheromatous plaque leading to thrombi formation and coronary spasm.

AIM

To report the immediate and late results of coronary angioplasty in patients with unstable angina.

PATIENTS AND METHODS

Eight hundred twenty eight patients were subjected to coronary arteriography between January 1994 and June 1996. Of these, 242 were subjected to a transluminal coronary angioplasty, 245 patients were subjected to surgical revascularization and 341 patients were treated without revascularization.

RESULTS

A total of 323 stenotic lesions (1.3 lesions per patient) were subjected to angioplasty. Angiographic success was obtained in 93% of patients. Angiographic success and lack of major complications such as death, infarction of the need for surgery, was obtained in 90% of patients. Five patients (2.1%) had a non fatal infarction and five required emergency surgery. Hospital mortality was 1.2%. During the year of follow up, 15% required a new revascularization, 3.3% had a non fatal infarction and 3.3% died.

CONCLUSIONS

Coronary angioplasty had a 90% immediate success and 78% of patients were free of ischemic events after one year of follow up.

[Rotational atherectomy (Rotablator) for percutaneous transluminal coronary angioplasty]

BACKGROUND

The use of Rotablator in percutaneous transluminal coronary angioplasty attempts to reduce the atheromatous plaque abrading it and fragmenting the parietal calcium of the artery.

AIM

To report our experience with the use of Rotablator.

PATIENTS AND METHODS

Rotational atherectomy was performed in 189 patients aged 60.8 +/- 11 years (154 men). The clinical indication for the procedure was chronic angina in 22%, unstable angina in 44%, myocardial infarction in 21%, silent angina in 7% and re-stenosis in 6%. One hundred seventy seven patients were followed for a mean of 15.9 +/- 6.3 months.

RESULTS

Two hundred thirty six stenoses in 215 coronary arteries were treated with a 98.7% angiographic success rate. One patient had a Q infarction and no patient died or required emergency surgery. Fourteen patients had rises in CK MB enzymes (non Q infarction). Three patients had a pseudoaneurism and three had bleedings that required transfusion. Of the followed patients, 33 had a clinically suspected re-stenosis, that was angiographically confirmed in 23. Cardiac mortality was 2.3%. Seventy nine percent of patients had an evolution without angina or coronary events.

CONCLUSIONS

Percutaneous transluminal coronary angioplasty with the use of Rotablator had a high immediate success rate and a low incidence of complications. The clinical evolution of patients has been favorable with a low incidence of mortality and ischemic events.

[Hospital course of acute myocardial infarction: significance of the therapeutic procedures of early reperfusion]

Reperfusion therapy has contributed to decreased morbidity and mortality in patients with acute myocardial infarction (AMI). Implementation of thrombolytic therapy; primary angioplasty and emergency coronary artery by-pass surgery have proved to be effective in well designed controlled clinical trials. There is little information, however, about the impact of reperfusion therapy in the general clinical population that is usually seen in the coronary care unit. In this paper we have compared the clinical course, morbidity and mortality of patients attended for a first AMI in 2 different periods. Group I comprised 431 patients seen during the period 1981-1986 and group II bad 113 patients seen during the period 1992-1993. Age, gender distribution and AMI location were similar in both groups. Patients in group I had a significantly higher incidence of tobacco use and previous angina pectoris. In group I, 4% of patients received streptokinase, 0.9% of patients had emergency by-pass surgery and none had primary angioplasty, whereas in group II, 29% of patients received trombolytics, 6.5% had primary angioplasty and 6.5% had by-pass surgery. Heart failure Killip class II-III occurred in 35% of patients in group I and in 13% of patients in group II (p < 0.05). Intrahospital mortality was 19.6% in group I and 11.5% in Group II (p < 0.045). There were no differences in the incidence of cardiogenic shock in both groups. Multivariate analysis showed that age and heart failure were significant independent predictors of mortality in both periods. Thus, there has been a significant change in the therapeutic approach to AMI patients in recent years. Widespread utilization of reperfusion therapy appears to be associated with decrease in morbidity and mortality in a general population of patients with a first AMI.

[Radiofrequency fulguration of accessory pathways]

Between August 1991 and August 1993, 75 patients (42 male) with Wolff Parkinson White syndrome (43 concealed) were subjected to radiofrequency ablation of accessory pathways at our institution. 55 had left, 8 postero septal, 2 anteroseptal and 10 right accessory pathways. A retrograde aortic technique with placement of the ablation catheter in close proximity to the mitral annulus was used for most of the patients with left accessory pathways and for some with posteroseptal pathways. The right, anteroseptal and some posteroseptal pathways were ablated using a right heart approach placing the ablation catheter in the tricuspid annulus. Ablation was successful in 61 patients (81%). One subject developed a fatal cardiac tamponade after a transeptal catheterization and was unrelated to the ablation per se. It is concluded that radiofrequency ablation of accessory pathways is a curative procedure for a great majority of patients with Wolf Parkinson White syndrome.

[Primary coronary angioplasty as early reperfusion treatment of acute myocardial infarction]

Between March 1990 and July 1993, 21 patients with an evolving acute myocardial infarction were treated with coronary angioplasty after 2-9 hours of chest pain (mean 3.9). Thirteen had a clinically and electrocardiographically large infarction, including 3 in cardiogenic shock. The dilated arteries were the left anterior descending in 14, the left circumflex in 4 and right coronary artery in 3 patients. With angioplasty successful reperfusion of the infarct area was obtained in 18 patients (86%). The procedure was well tolerated by most patients and the in-hospital mortality rate was 5%.

[Early test of thallium dipyridamole after myocardial infarction: prognostic value and correlation with coronarography]

Fifty three patients were studied with dipyridamole thallium myocardial scintigraphy, 4 to 6 days after a first episode of myocardial infarction. Localization of infarction was anterior in 25 and inferior in 28. Infarction was confirmed by myocardial scintigraphy in 87% of cases. A non q wave myocardial infarction was present in 5 of the 7 patients with negative scintigraphy. Residual myocardial ischemia was suggested by myocardial scintigraphy in 68% of patients. Correlated to coronary arteriography, sensitivity for myocardial ischemia was 80%, specificity 82%. After a mean follow up of 11.2 months, 22 of 36 patients with positive myocardial scintigraphy had new coronary events, 15 of them requiring myocardial revascularization. In contrast, only 2 of 17 patients with negative scintigraphy had new events (p < 0.05). Thus dipyridamole thallium myocardial scintigraphy early after myocardial infarction is a valuable prognostic test.

[Early systemic thrombolysis in acute myocardial infarction: clinical and angiographic results]

Systemic thrombolysis is an effective therapy for acute myocardial infarction, since it restores coronary flow and contributes to preserve left ventricular function. We analyze our experience with intravenous thrombolytic therapy in 45 cases with acute myocardial infarction treated within 6 hours of onset of symptoms. 28 patients had anterior and 17 inferior myocardial infarction. We treated 38 patients with streptokinase 1 to 1.5 million units infused during a 30 to 60 minute period and 7 patients with tissue plasminogen activator factor, 100 mg infused during 2 hours. Regression of chest pain and ST segment elevation and early CPK peaking (less than 4 hours) were utilized as criteria for reperfusion. Accordingly 29 patients (64%) met these criteria. Coronary angiogram was performed within 7 days in 38 patients. It disclosed a patent coronary artery in the infarcted area in 28 cases (74%). Transient hypotension with thrombolytic therapy was observed in 17 patients (38%) and bleeding complications in 3 cases (7%). Two patients (4%) died early after therapeutic failure. In summary we have confirmed that intravenous thrombolytic therapy is safe and effective in the early period of myocardial infarction and that is associated with a high incidence of clinical and angiographic reperfusion.

[Sudden death in the young adult without demonstrable cardiopathy: the clinical and electrophysiological characteristics in 3 cases]

We report 3 young adult males who developed spontaneous ventricular fibrillation in the absence of demonstrable heart disease. Extensive clinical and electrophysiologic evaluation failed to disclose a cause for the arrhythmia. Antiarrhythmic drugs were empirically used in all patients but 2 of them eventually died. Thus, unexplained ventricular fibrillation without demonstrable heart disease carries a serious short-term prognosis. An implantable cardio-vector-defibrillator may be the therapy of choice in these cases.

[Serum lipids, HDL2 and HDL3 cholesterol and apolipoproteins A1 and B as predictors of coronary artery disease diagnosed by coronarography]

Serum levels of total, HDL2 and HDL3 cholesterol, triglycerides and apolipoproteins A1 and B were compared in 100 Chilean males with (n = 80) or without (n = 20) coronary artery disease (CAD). The presence and severity of CAD was determined by an angiographic score. Discriminating power, sensitivity, specificity and positive predictive value for CAD were calculated for all variables. As an isolated factor, total cholesterol had the greatest discriminating power (p less than 0.002): 21% of patients with CAD had cholesterol levels below 200 mg/dl while no patient with cholesterol over 275 mg/dl was free of disease. Even though all cases with HDL cholesterol below 25 mg/dl belonged in the CAD group, this factor had no overall discriminating power. Total cholesterol/HDL cholesterol ratio had the greatest discriminating power (p less than 0.001) while total/HDL2 cholesterol had the best positive predictive value.

[Atrial ectopic tachycardia. A variety of incessant tachycardia]

A 19 year old patient with incessant supraventricular tachycardia was submitted to electrophysiologic study. An ectopic left atrial focus was demonstrated. Intraoperative mapping localized the focus to the upper left atrial quadrant. Successful surgical isolation of the focus was possible. The patient is currently asymptomatic and arrhythmia free.

[Are there any differences between myocardial infarction with Q and non-Q in ECG]

Recent literature provides evidence that Non-Q wave myocardial infarction (Non-Q MI) has a different intrahospital course and prognosis than Q-wave myocardial infarction (Q-MI). We evaluated clinical and laboratory characteristics, complications and therapeutic requirements of 557 consecutive patients, 440 with Q-MI and 117 with Non-Q MI. Risk factors for coronary artery disease did not differ among groups. Non-Q MI patients had a significantly higher incidence of previous cardiac events such as myocardial infarction, angina pectoris and heart failure. Peak CPK enzyme values were significantly lower in Non Q MI patients (952 +/- 753 vs 1,743 +/- 1,425 VI/l p less than 0.05). Early complications were different for both groups: The incidence of heart failure, ventricular arrhythmias and conduction defects was lower in Non-Q MI patients while the incidence of unstable angina pectoris and need for aorto coronary by-pass surgery was higher (18 vs 12%, 17 vs 7% respectively, p less than 0.05). Mortality was not different (8.4% in Non-Q MI vs 12.3% in Q MI). Thus, Non Q MI appears to have a more benign clinical course than Q-MI in terms of less complications such as heart failure, ventricular arrhythmias and conduction defects. However, Non-Q MI is a potentially unstable clinical entity with a higher incidence of early post MI angina pectoris requiring a more aggressive medical and surgical therapy.

Acute effect of systemic versus intracoronary dipyridamole on coronary circulation

Dipyridamole has been proposed as an ideal agent to evaluate coronary vascular reserve because it produces selective coronary vasodilation without systemic hemodynamic effect. The actions of intracoronary (IC) and intravenous (IV) dipyridamole on coronary blood flow and systemic hemodynamics were compared in 15 patients with chest pain syndrome and normal coronary arteries. They received IC dipyridamole, followed 10 minutes later by 0.5 mg/kg of IV dipyridamole. IC dipyridamole produced a 73% increase in coronary sinus flow without hemodynamic changes, except for a slight increase in pulmonary systolic and diastolic pressures. IV dipyridamole administration produced an additional 88% increase in coronary sinus flow, reaching 172% over baseline; it was also associated with a significant (p less than 0.01) increase in heart rate (78 +/- 14 vs 102 +/- 19 beats/min), cardiac index (4 +/- 0.7 vs 6.3 +/- 1.7 liters/min/m2), and pulmonary artery systolic (27 +/- 5 vs 34 +/- 7 mm Hg) and diastolic pressures (12 +/- 4 vs 19 +/- 7 mm Hg). These data suggest that the coronary vasodilatory effect seen after IV dipyridamole administration is related to mechanisms other than direct coronary vasodilation.

Effect of intravenous dipyridamole on regional coronary blood flow with 1-vessel coronary artery disease: evidence against coronary steal

The effects of i.v. dipyridamole were studied in 9 patients with isolated total left anterior descending coronary artery (LAD) obstruction, in 6 patients with isolated 90 to 99% diameter reduction of the LAD and in 10 patients with normal coronary arteries and normal left ventricular function. Coronary sinus and great cardiac vein flows were determined by continuous thermodilution. Flows were measured at rest and 1, 3, 5 and 10 minutes after i.v. dipyridamole. Great cardiac vein flow represents the venous outflow from the LAD territory. In the presence of coronary steal from the LAD territory, great cardiac vein flow is expected to decrease while coronary sinus flow increases. Intravenous dipyridamole induced a similar flow increase in the coronary sinus and the great cardiac vein in all 3 groups (p less than 0.001 between rest and dipyridamole, difference not significant among groups), suggesting that no coronary steal was induced. The maximal increase in great cardiac vein flow was 118 +/- 74% in the control group, 86 +/- 74% in the group with 90 to 99% LAD obstruction and 102 +/- 29% in the group with total LAD obstruction (difference not significant). These data show that i.v. dipyridamole produces a similar increase in coronary flow in ischemic and nonischemic areas and suggests that an increase in collateral flow is the underlying mechanism for increased flow to the ischemic area.

Acute myocardial infarction with normal coronary arteries. In vivo demonstration of coronary thrombosis during the acute episode

Two cases with acute myocardial infarction are presented. Both had thrombotic occlusion of the infarct-related artery. Following successful thrombolysis with streptokinase, coronary angiography was normal. These cases prove that "myocardial infarction with normal coronaries" can be associated with coronary thrombosis in the acute stage.

Large V waves in the pulmonary capillary wedge pressure tracing without mitral regurgitation: the influence of the pressure/volume relationship on the V wave size

We have previously demonstrated that a large V wave in the pulmonary capillary wedge tracing may occur in the absence of mitral regurgitation. This study evaluates the role of left atrial and pulmonary vein compliance on such a finding. We studied 11 patients with coronary disease, without clinical or angiographic mitral regurgitation. Heart rate, pulmonary capillary wedge mean, A and V waves, V-wave slope, left ventricular and aortic pressures, cardiac output, and left atrial echo and apical phonocardiogram were recorded simultaneously. Preload was modified acutely by volume overload and by the administration of i.v. nitroglycerine. Volume administration induced a marked increase in V-wave pressure (13.0 +/- 9.6 vs. 27.0 +/- 9.6 mmHg, p less than 0.05), without producing mitral regurgitation, and without appreciable change in left atrial dimension by echo (33.0 +/- 4.9 vs. 35.5 +/- 5.2 mm, NS), or stroke volume (101.7 +/- 26.2 vs. 97.8 +/- 34.3 ml, NS). An increase was also seen in the A wave (13.6 +/- 8.9 vs. 23.3 +/- 8.5 mmHg, p less than 0.05), pulmonary capillary wedge mean pressure (9.8 +/- 7.2 vs. 20.6 +/- 7.8 mmHg, p less than 0.05), and left ventricular diastolic pressure (7.4 +/- 5.5 vs. 14.6 +/- 6.3 mmHg, p less than 0.05). All values returned to baseline after nitroglycerine. The compliance of the left atrium/pulmonary veins decreased with increasing pulmonary capillary wedge pressures. With large filling volumes, a small stroke volume brings on a large pressure change, thus explaining the finding of large V waves in patients with elevated pulmonary capillary wedge pressure and without mitral regurgitation.

Association of coronary artery disease and valvular heart disease in Chile

This study analyzes the prevalence of coronary artery disease (CAD) among patients with rheumatic valvular heart disease (VHD) in Chile. Coronary angiography was performed in all patients referred to cardiac catheterization with VHD who were over age 50 years and who had angina or ECG signs of ischemia. A total of 100 patients entered the study. Significant CAD (greater than 50% obstruction) was found in 14% of the cases: 7% in patients with mitral valve disease (MVD), 18% in aortic valve disease (AVD), and 21% in combined mitral and aortic valve disease (MAVD). Angina was present in 14% of the patients with MVD, 63% with AVD, and 53% with MAVD. Only 57% of patients with CAD had angina pectoris; 20% with angina had CAD. Hemodynamic parameters and left ventricular ejection fraction were not correlated with the presence or absence of CAD. We conclude that in patients with valvular heart disease, the incidence of CAD is lower in Chile than previously reported in the English literature. We confirmed the fact that angina is often not associated with CAD, and that CAD is often present in the absence of angina.

Abnormal regional myocardial flow in myocardial bridging of the left anterior descending coronary artery

A patient with angina pectoris, myocardial bridging of the left anterior descending coronary artery and otherwise normal coronary arteries is presented. Regional myocardial blood flow was studied with the thermodilution technique. Atrial pacing of the heart at a rate of over 140/min reproduced the anginal syndrome, with S-T segment depression in the electrocardiogram. There was a transient decrease in great cardiac vein flow during rapid pacing with a simultaneous increase in total coronary sinus flow. The study demonstrates that in this patient, a myocardial bridge was associated with decreased blood flow to the area perfused by the bridged artery with a concomitant increase in coronary sinus flow as the pacing rate was increased from 96 to 150 and 180/min. After administration of nitroglycerin, the bridging effect was more accentuated on angiography; pacing-induced tachycardia was associated with similar changes in great cardiac vein and coronary sinus flows with less S-T segment depression in the electrocardiogram and chest pain of milder intensity.