Isolated noncompaction of the myocardium: an exceedingly rare cardiomyopathy. A case report

Isolated noncompaction of the left ventricular myocardium is a rare cardiac disorder due to an arrest in myocardial morphogenesis. It is characterized by prominent and excessive trabeculation in a ventricular wall segment, with deep intertrabecular spaces perfused from the ventricular cavity. Echocardiographic findings are important clues for the diagnosis. Clinical symptoms include signs of left ventricular systolic dysfunction even to the point of heart failure, ventricular arrhythmias, and embolic events. We describe an adult case in whom the only clinical symptoms were life-threatening ventricular arrhythmias. Transthoracic echocardiography did not contribute to the diagnosis, which was made thanks to left ventricular contrast angiography. Electrophysiological testing induced a fast monomorphic sustained ventricular tachycardia, with hemodynamic impairment, that was refractory to pharmacological treatment, and for this reason a permanent cardioverter-defibrillator was implanted. A subsequently performed transesophageal echocardiographic examination showed a localized, regional increase in left ventricular wall thickness and degree of trabeculation. The causes and electrophysiological mechanisms of arrhythmias in noncompaction are still unknown: grossly irregular branching and connecting of myocardial fascicles in the noncompacted segments, isometric contraction with increased wall stress, and localized coronary perfusion impairment can all induce disorganized or delayed activation and increase the potential for arrhythmias. This is the first reported case of noncompaction in which an implantable defibrillator was used to control life-threatening arrhythmias.

[The exercise test with atropine]

BACKGROUND

Exercise testing remains the most accessible and widely used technique for the detection of coronary artery disease (CAD) and for the assessment of its severity. Clinical usefulness of the simple exercise test is limited by poor sensitivity and imperfect specificity. Many patients referred for diagnostic stress testing cannot achieve an adequate increase in heart rate due to lack of motivation, poor physical condition, or medications. Atropine increases the heart rate and therefore myocardial oxygen consumption, and might improve the diagnostic accuracy of exercise testing, either reducing the number of non-diagnostic examinations, or increasing the positivity of the test in patients with non severe coronary disease.

METHODS

One-hundred-seventy-two consecutive patients (144 males and 28 females, age 58 +/- 8 years) with suspected coronary artery disease underwent exercise testing and coronary angiography. Exercise testing was considered positive in the presence of ST segment depression > or = 0.10 mV horizontal or downsloping, > or = 0.15 mV upsloping, or in the presence of ST elevation without Q waves. The test was considered negative in the absence of significant ST depression or elevation if the exercise heart rate was > 85% of age-predicted maximum, non-diagnostic if the heart rate was < 85%. In 148 patients (86%) coronary angiography showed CAD (> 70% luminal reduction in at least one major vessel), in 24 patients (14%) non significant CAD or angiographically normal coronary arteries (NoCAD). Exercise testing was positive in 134 patients (78%: 85% in CAD, 33% in NoCAD), negative in 13 patients (8%: 3% in CAD, 38% in NoCAD), non-diagnostic in 25 patients (14%; 12% in CAD, 29% in NoCAD). The sensitivity was 85%, specificity was 38%, and diagnostic accuracy 78%. In the 25 patients with non-diagnostic test (18 CAD, 7 NoCAD) the exercise was repeated 30-90 minutes later, immediately after i.v. injection of 1-2 mg of atropine, and was stopped at the same workload of the index test.

RESULTS

The atropine-exercise test was well tolerated and accomplished in all cases. The maximal heart rate (139 +/- 11 vs 121 +/- 11) and the double product (25,308 +/- 4082 vs 22,166 +/- 3569) were significantly greater after atropine. The increase of the maximal heart rate improved the detection of the electrocardiographic signs of exercise-induced myocardial ischemia only in CAD patients. In the 18 CAD patients the atropine-exercise test was positive in 8, negative in 5, non-diagnostic in 5. In the 7 NoCAD patients the atropine-exercise test was positive in 1, negative in 6. The test remained non-diagnostic only in 3% of patients. The sensitivity of the test with atropine was 91%, specificity was 63%, and diagnostic accuracy 87%.

CONCLUSIONS

The addition of atropine to exercise testing, which causes further chronotropic stress to the myocardium, is well tolerated and safe, and improves the diagnostic accuracy of the test for the detection of coronary artery disease in patients who cannot achieve an adequate exercise heart rate. The combination with atropine increases the utility and the cost-effectiveness of exercise testing.

Digital stress-echocardiography using a public domain program for the Macintosh personal computer

Left ventricular wall motion abnormalities secondary to stress-induced myocardial ischemia can be detected with difficulty by mentally comparing echocardiographic images sequentially recorded on videotape. Digital stress-echocardiography, a combination of ultrasound imaging and digital archiving technologies, at least partially can overcome this problem: the technique is based on reviewing images at rest and after stress (exercise or pharmacological) side by side in dual- or quad-screen digital format, in a synchronized cine-loop, as if obtained simultaneously. This technique however is presently not widely used, due to the high cost of most commercially available systems. We have developed a digital stress-echo system, which is easy to use and relatively inexpensive, running on a Macintosh II personal computer with 8-bit graphics. The 2-D echocardiographic images recorded on videotape are digitized offline using a video digitizing board. The image can be displayed and analyzed using the public domain NIH image software developed by Wayne Rasband, without loss in image quality and resolution, particularly if using Super-VHS videotape. We have made a macro procedure for the montage in a quad-screen format of four digital recorded echocardiographic cardiac cycles of six frames that takes only a little more time than commercially available systems. In conclusion, the use of a personal computer and low-cost software may help to make digital stress-echo techniques more widely feasible in the clinical setting and increase the diagnostic power of the ultrasound technique in the evaluation of patients with known or suspected coronary artery disease.

[Acute myocardial ischemia: ECG or echocardiography? Considerations on a clinical case]

We present a clinical case and a review of the literature on the usefulness of two-dimensional echocardiography for the diagnosis of acute myocardial ischemia in patients presenting with chest pain but without diagnostic electrocardiographic changes. The case refers to a patient admitted a few hours after an episode of prolonged chest pain without diagnostic electrocardiographic changes, but with a severe wall motion abnormality assessed by two-dimensional echocardiogram. The electrocardiogram obtained 24 hours after admission showed giant negative T waves in the anterior chest leads when the patient was asymptomatic and the echocardiogram showed disappearance of wall motion abnormalities. Coronary angiography demonstrated a thrombotic occlusion of the left anterior descending coronary artery, that was treated by transluminal angioplasty. The considerations refer to the following points: 1) a substantial portion of patients with chest pain examined in the emergency room has initially a normal or non-diagnostic electrocardiogram; 2) in these patients two-dimensional echocardiography provides a highly sensitive and specific noninvasive tool for the establishment of the correct diagnosis of acute myocardial ischemia when a severe wall motion abnormality is shown; 3) if successive amelioration of regional myocardial dysfunction is assessed, this was probably due to stunned myocardium; 4) it is probably not correct to consider T wave inversion as the electrocardiographic equivalent of myocardial stunning, as the two phenomena are not chronologically correlated.

[The aneurysmal degeneration of aortocoronary bypasses. A case report]

A 67-year-old man presenting with oppressive atypical chest pain 13 years after aorto-coronary saphenous vein bypass surgery, was found to have a large left anterior mediastinal mass on chest x-rays. Computerized tomography and digital subtraction angiography showed conflicting evidence on the vascular nature of the structure: the suspect diagnosis was of aortic pseudoaneurysm originating in the area of previous aortic cannulation. Selective coronary and bypass angiography showed extreme irregularity and dilatation of the grafts, and revealed the mediastinal mass to be represented by aneurysmal dilatation of the saphenous vein graft to the obtuse marginal coronary artery, partially filled with thrombus. At operation, another smaller aneurysm was found on the right coronary artery graft. Aneurysmal degeneration of vein grafts in the coronary circulation is exceedingly rare, and in only 6 reported cases has such an aneurysm presented as a mediastinal mass. To our knowledge, this is the first case in which an aneurysmal dilatation involved two saphenous vein coronary grafts.

[Coronary angioplasty in postinfarct angina]

BACKGROUND

The recurrence of transient myocardial ischemia is a frequent event in the course of acute myocardial infarction. Postinfarction angina develops more frequently after a non-Q wave infarction, and after effective thrombolysis; when uncontrolled by standard medical treatment, it is associated with an increased incidence of unfavorable cardiac events. Therapeutic strategies involve aggressive medical therapy, frequent use of early angiography, and mechanical coronary revascularization with bypass surgery or transluminal coronary angioplasty (PTCA).

PATIENTS

We retrospectively examined 68 consecutive patients treated with PTCA for postinfarction angina. Of the whole, 36 (53%) had sustained a non-Q wave infarction; 29 (43%) had been treated with thrombolysis in the acute phase. Ischemia was in the infarction zone in 94% of cases; mean EF was 61.5 +/- 12%, and in 18 cases EF was < 55%.

RESULTS

In 7 cases two arteries were dilated. There were no deaths related to the procedure. The overall success rate was 91.2%. Major complications occurred in 2 cases (1 acute occlusion with reinfarction, 1 major dissection requiring emergency surgery). The results are analyzed according to the time interval between index infarction and PTCA. In 28 cases (Group A) PTCA was performed within 30 days due to medically refractory symptomatology; in 40 cases (Group B) PTCA was postponed to beyond 30 days from infarction. In Group A involvement of the left anterior descending coronary artery was more frequent (75% of cases vs 40%; p = 0.009). The success rate in Group A was slightly lower than for Group B (85.7% vs 95%); the incidence of complications was higher (7.1% vs 0%), although not statistically different. At 6 month follow-up a restenosis was found in 10 cases (16% of successful PTCAs, 21% of angiographic controls).

CONCLUSIONS

We conclude that for patients with postinfarction angina, selected for a suitable coronary anatomy, PTCA is an effective therapeutic option, with a high success rate, low immediate morbidity, and good mid-term results. The risk of intraprocedural complications appears only slightly higher for patients with unstable symptoms, who undergo PTCA earlier after infarction.

[Angiographic morphology of coronary lesions in various syndromes of ischemic cardiopathy]

The angiographic morphology of coronary lesions is often completely ignored in the prognostic and decision-making process related to patients with coronary disease. We performed this study to evaluate the possibility of identifying complex or complicated atherosclerotic lesions by means of routine diagnostic coronary arteriography, and to assess their prevalence in the different syndromes of ischaemic heart disease. From an overall group of 200 successive cases studied using coronary angiography, 111 patients with significant coronary artery disease in whom a "culprit lesion" could be identified were retrospectively selected. The angiographic morphology of coronary lesions was defined according to an original classification as: 1) simple stenosis, 2) complex lesion, 3) thrombosis. Of the 111 patients, 36 had been studied for stable angina, 31 for unstable angina, 10 for a non-Q wave myocardial infarction, 34 for transmural infarction. The clinical groups did not show any significant differences when compared on the basis of number of vessels involved and degree of narrowing of the ischaemia-producing artery. Significant differences were found when angiographic morphology was analyzed. In stable angina 78% of ischaemia producing lesions appeared as simple stenoses, while 92% of the unstable or more severely ischaemic patients exhibited complicated lesions (p less than 0.001). In unstable angina and non-Q infarction a complex lesion was present respectively in 71% and 60% of the cases; clear-cut intraluminal thrombosis was demonstrated in 23% of unstable angina, in 30% of non-Q wave infarction and in 39% of transmural infarction (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary hypertension in isolated aortic stenosis. Hemodynamic correlations and follow-up

The clinical, hemodynamic, and angiographic data on 92 patients with severe isolated aortic stenosis were reviewed to determine the incidence and mechanism of pulmonary hypertension. The status of each of these patients was determined 1 to 8 years after diagnosis by cardiac catheterization. Patients were divided into three groups on the basis of the pulmonary artery systolic pressure: group 1 (less than or equal to 30 mm Hg), 46 patients; Group 2 (31 to 50 mm Hg), 31 patients; and Group 3 (greater than 50 mm Hg), 15 patients. The prevalence of pulmonary hypertension was 50% (46/92) and that of severe pulmonary hypertension, 16% (15/92). There was no significant difference in age, aortic valve gradient, or valve area among the three groups. There was a significant positive correlation in left ventricular end-diastolic pressure (group 1, 15.5 +/- 7.2 mm Hg; group 2, 23.3 +/- 8.1 mm Hg; and group 3, 29.5 +/- 5.8 mm Hg; R = 0.56, p less than 0.01). There was also a significant negative correlation in left ventricular ejection fraction (group 1, 67.5% +/- 14%; group 2, 62.3% +/- 13.8%; and group 3 49.9% +/- 18.3%; R = 0.43, p less than 0.01). Of the 92 patients, 85 had aortic valve replacement with four (4.7%) hospital deaths. Follow-up showed excellent symptomatic relief in all three groups. Thirteen of the 15 patients in group 3, with severe pulmonary hypertension, had aortic valve replacement. There were no hospital deaths and only one noncardiac death at follow-up in Group 3 patients, and 11 of the 12 surviving patients were in New York Heart Association functional class I. We conclude that pulmonary hypertension is common in isolated aortic stenosis and is related to an elevated left ventricular end-diastolic pressure, frequently with preserved systolic function. Surgical results are excellent.

Pulmonary hypertension in severe aortic stenosis. Incidence, mechanisms, clinical and surgical implications

Pulmonary arterial hypertension in aortic stenosis (AS) is considered uncommon, and the possible mechanisms involved in its insorgence are only speculative. We analyzed a group of 95 patients with severe AS (mean systolic gradient greater than or equal to 50 mmHg and/or aortic valve area less than or equal to 0.7 cm2) studied by standard hemodynamic techniques. In the study group the incidence of pulmonary hypertension was 50.5%. We divided the overall population in: Group I (47 patients), with systolic pulmonary artery pressure (PAP) less than or equal to 30 mmHg; Group II (33 patients), with moderate hypertension (PAP 31-50 mmHg); Group III (15 patients), with severe hypertension (PAP greater than 50 mmHg). Subjects with pulmonary hypertension were slightly older, and had more severe obstruction to left ventricular (LV) outflow. Impairment of LV diastolic function in the presence of pulmonary hypertension was expressed by a highly significant increase of LV end-diastolic pressure (p less than .001); reduced ejection performance was represented by a significant decrease of ejection fraction (p less than .01). Pulmonary vascular resistances also appeared to be increased. The correlation between variables showed PAP to be strongly correlated in a positive way to the LV end-diastolic pressure, and in an inverse way to the LV systolic performance (p less than .001 for both). Less striking was the correlation of pulmonary vascular resistances to LV diastolic and systolic function: a reactive and reversible vasoconstriction seemed likely. Surgery was not performed in 8 of the 95 patients: 5 of them died shortly after diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transluminal coronary angioplasty: is a learning curve necessary?]

Transluminal coronary angioplasty is a complex technique, and a lesser percentage of success, or "learning curve", is reported in the initial experience of several investigators. Is reported here an initial series of 20 consecutive cases treated by coronary angioplasty for single vessel coronary disease with favourable results. After a meticulous medical treatment, coronary angioplasty was performed in the 20 cases with a "steerable" catheter and guide system and step-wise pressure inflations. In only 1 case (5%), with highly unstable clinical conditions and "unfavourable anatomy", the technique was followed by emergency aorto-coronary bypass and myocardial infarction. In 19 cases (95%) clinical and angiographic success was obtained, with a significant reduction of the mean measured coronary artery stenosis from 84.8 +/- 10.5% to a post-dilatation value of 15.6 +/- 10.5% (p less than 0.001). Coronary artery occlusion due to spasm or thrombosis or coronary dissection were never observed. This favourable series demonstrates that nowadays with the improved technology and with a scrupulous pharmacological protocol transluminal coronary angioplasty can be performed with a low incidence of complications and excellent results, further assessing its high potential in the treatment of ischemic coronary artery disease.

[Paroxysmal supraventricular tachycardia in infants as a clinical manifestation of dilated cardiomyopathy]

Two cases are described of infants in whom paroxysmal supraventricular tachycardia was the first clinical manifestation of an underlaying dilatating cardiomyopathy. To stop the tachycardia in such cases drugs without inotropic negative effect are recommended.

[Prediction of the presence and severity of coronary arteriopathy and left ventricular dysfunction by discriminant multivariate analysis of the exercise test]

266 male p., with chest pain and without previous myocardial infarction were studied by exercise test and coronary arteriography. 17 had no coronary disease (group C-0), 22 had less than or equal to 50% coronary stenosis (C-1), 65 had severe 1 vessel disease (C-2), 73 had 2 vessel disease (C-3), 89 had 3 vessel disease (C-4). 95 had normal ventricular function (group V-0), 111 had hypokinetic ventricular segments (V-1) and 60 had akinetic ventricular segments (V-2). 11 exercise test variables were stepwise selected to discriminate the C-groups and the V-groups. For C-groups significant variables were: test result, heart rate increment, number of leads, work load, rate-pressure product, systolic pressure increment. By 4 discriminant functions, 41% p. were correctly classified. For V-groups significant variables were: hear rate increment, test result, effort angina, rate-pressure product, number of leads, ST depression, ST configuration, age. By 2 discriminant functions 53% p. were correctly classified.

[The diagnosis of prosthesis pathology in biological and mechanical valves. I. Clinical and echocardiographic evaluation]

We retrospectively evaluated the clinical and echocardiographic findings of 50 patients with documented malfunctioning of cardiac prosthetic valves. The prostheses, mechanical or biological, were in 24 cases in a mitral and in 26 cases in an aortic position. Prosthetic dysfunction was due to thrombosis, fibro-calcific degeneration, fibrous cloth, bacterial infection, dehiscence, mismatch. The clinical features were represented by cardiac insufficiency of different degrees, up to global congestive failure unresponsive to medical treatment, by sudden low-output syndrome, arrhythmias, angina. The changes in auscultatory findings have appeared important clues to prosthetic malfunction, but we stress the necessity of an instrumental documentation of the type and grade of dysfunction. Echocardiography has represented an essential tool for a rapid and accurate noninvasive diagnosis of prosthetic pathology. The echocardiographic examination, except 2 false negatives, has consistently provided informations useful for therapeutic decisions. In 7 cases in critical clinical conditions (refractory heart failure or shock) the echocardiographic examination has afforded the exact documentation and identification of prosthetic pathology, allowing by itself a surgical decision.

[Prosthetic pathology of mechanical and biological valves in the mitral and aortic position. II. Hemodynamic-angiographic evaluation and anatomo-surgical aspects]

The catheterization parameters of 42 patients with surgically confirmed prosthetic valve malfunction were retrospectively analyzed in order to evaluate the role of hemodynamic and angiocardiographic examination in the diagnosis of prosthetic complications. The invasive investigation provided in all cases more precise informations regarding the type and grade of prosthetic malfunction as compared to noninvasive techniques. Transvalvular gradients could be quantified, the amount of regurgitation could be defined and associated lesions (paraprosthetic aneurysms, aortic root dissection, fistulas secondary to bacterial endocarditis) could be recognized. The surgical exploration confirmed prosthetic malfunction in all cases except two, with fibrous tissue ingrowth: at the moment this complication is not distinguishable from thrombosis and no specific diagnostic signs have been described either with invasive or noninvasive techniques. In our experience the patients who can benefit from hemodynamic examination are: patients with echocardiographic examination of poor technical quality, patients in whom noninvasive investigations can not completely explain the clinical status ("false negative" echocardiograms, multiple prosthetic valves), all cases in whom cardiac surgery requires a precisely detailed evaluation of the prosthetic malfunction. The opportunity or necessity to perform an invasive study in patients with clinically suspected or proven prosthetic malfunction should be discussed individually.

[Identification of patients with stenosis of the main trunk of the left coronary artery by ergometric variables]

In 354 patients with coronary artery disease (9 with greater than or equal to 90%, 42 with 50-75% and 303 with no left main (LM) stenosis, prevalence of ergometric criteria of severe disease was considered. In patients with LM stenosis were more frequent: work load less than or equal to 75 watt (p less than 0,001); ST depression greater than 2 mm (p less than 0,01); 3 or more leads involved (p less than 0,05); no increment of heart rate (p less than 0,01) or of blood pressure (p less than 0.01). Work load had the best predictive value (30%) of LM stenosis, associated with a reasonable sensitivity (55%). Combination ST depression + heart rate or work load + blood pressure had a predictive value of 100%, but minimal sensitivity (8%). In detecting greater than or equal to 90% LM stenosis heart rate had the best predictive value (13%), associated with high sensitivity (78%). Presence of 2 any criteria could detect all greater than or equal to 90% LM stenosis (sensitivity 100%, predictive value 11%). ST depression + heart rate had a predictive value of 100% and a sensitivity of 44%. It is concluded that no single or associated exercise variable has both high sensitivity and high predictive value of LM stenosis.

[The pressure-dimension curve and midwall stress. Use of a combined hemodynamic-echocardiographic method and correlation with contrast ventriculography]

An invasive (left ventricular pressure recording) and a noninvasive technique (M-mode echocardiography) were combined during the hemodynamic study of 15 patients with various degrees of left ventricular impairment, in order to provide left ventricular function parameters independent from contrast studies. Left ventricular pressure, dimension and wall thickness changes were continuously digitized on a computer system, which was able to derive the ventricular pressure-dimension loop and to calculate the midwall equatorial stress at end-diastole and peak-systole. The parameters derived from the loop (diastolic work, net systolic work, cycle efficiency) and midwall meridional and circumferential stresses were compared with the results of contrast ventriculography and with the wall hypertrophy index. Diastolic work appeared to be correlated with the systo-diastolic volume change; systolic work correlated with the ejection fraction; the cycle efficiency was inversely correlated with both end-diastolic and end-systolic volumes and directly correlated with the hypertrophy index. Midwall stress, both end-diastolic and peak-systolic, was strongly and positively correlated with ventricular volumes, while it decreased with increasing hypertrophy. Systolic stress increased with decreasing ejection fraction. The combined echo-pressure technique, through the evaluation of the pressure-dimension loop and the calculation of wall stress, can generate data of left ventricular function that allow a more complete assessment of left ventricular impairment.

Cardiac valve orifice equation independent of valvular flow intervals: application to mitral valve area computation in mitral stenosis and comparison with the Gorlin formula and direct anatomical measurements

An orifice equation is developed which relates the effective mitral valve area (A), the average mitral valve pressure gradient (dP), the cardiac output (Q) and the heart frequency (f) through considerations of momentum conservation across the mitral valve. The form of the new equation is A = (4.75 X 10(-5)Qf/dP, where A, Q, and dP are expressed in cm2, ml X min-1 and mmHg respectively. Mitral valve areas computed with the new orifice formula are found to correlate with those computed by the Gorlin formula in conditions of equilibrium associated with the resting state at a level of r = 0.95, SE = 0.15 cm2, with autopsy measurements at a level of r = 0.85, SE = 0.18 cm2 and with direct anatomical measurements of excised valves at a level of r = 0.78, SE = 0.41 cm2. The results suggest that the new formula may be considered as an independent orifice equation enjoying a similar domain of validity as the Gorlin formula. The new equation offers the possibility of deriving additional useful haemodynamic relationships when used in combination with established cardiological formulas.

Diagnosis of cardiac amyloidosis made by ultrastructural examination of endomyocardial biopsy. A case report

A case of cardiac amyloidosis is described in which clinical and scintigraphic findings were those of ischemic heart disease. Electrocardiogram disclosed low voltages in the peripheral leads and a pattern of anterior pseudo-myocardial infarction. 2D-echocardiography showed thickened cardiac walls and a "granular sparkling" appearance of the septum. The curve of the left ventricular diastolic pressure suggested impaired ventricular relaxation without a true dip-plateau morphology. Stains for amyloid of rectal biopsy specimens were negative. Histological study of left ventricular endomyocardial biopsy indicated the presence of basophilic material among the myocytes; at ultrastructural examination this infiltrating substance resulted to be amyloid. This case stresses the effectiveness of ultrastructural investigation of left ventricular endomyocardial biopsy in the diagnosis of infiltrative and/or metabolic cardiac disorders.

Cardiac ultrastructure in primary restrictive cardiomyopathy

A five-year clinical follow-up and the results of myocardial biopsies are described in a patient with primary restrictive cardiomyopathy. Histologic examination of a right ventricular endomyocardial biopsy taken early in the course of the illness was not contributory. Histologic examination of a left ventricular endomyocardial biopsy five years later showed hypertrophy and disarray of myocytes, thickening of the endocardium, and interstitial fibrosis. Connective tissue was compact and regularly oriented in the endocardium, but tangled and irregularly oriented in the interstitium. It is concluded that the irregular network of collagen fibrils and elastic fibers limits diastolic relaxation and prevents ventricular dilatation; that the coexisting hypertrophy results from an attempt to maintain normal pump function; and that the myocyte disarray is a consequence of abnormal mechanical forces generated under conditions of severe fibrosis.

Effects of the cold pressor test on the left ventricular function of patients with coronary artery disease

We used the cold pressor test as provocative of myocardial ischemia in 23 subjects evaluated for chest pain on effort. Seven of them (group N) had normal coronary arteries, and 16 (group CAD) had critical stenoses along the main branches of the left coronary artery. In both groups exposure to cold induced increase in arterial pressure and double product. Left ventricular end-diastolic pressure increased +60% from baseline (P less than 0.001). Angiocardiographic parameters, unchanged in group N, showed an impairment of left ventricular function in group CAD. End-diastolic volume increased +11% (P less than 0.01), ejection fraction decreased -8% (P less than 0.0025), with a significant reduction in segmental wall motion in the area of the diseased artery (P less than 0.001). The mean Vcf was slightly and not significantly reduced, while early-systolic and end-diastolic stress and the constant of stiffness consistently increased in both groups. The appearance or extension of ventricular wall contraction abnormalities in group CAD, in the absence of demonstrable coronary spasm and in the presence of a remarkable increase in left ventricular end-diastolic pressure and stress, was interpreted as due to ischemia secondary to increased extravascular resistances to coronary flow. The cold pressor test is proposed as a useful tool for the diagnosis and evaluation of patients with ischemic heart disease.

Left ventricular aneurysm. A radiographic method for quantitative angiocardiography with reconstruction of ventricular geometry

A method is presented for the measurement of ventricular aneurysms (An) by which the ventricle is considered to be composed of an ellipsoid or contracting portion and a hemispheroid or aneurysmal portion. Validation of the method with radio-opaque plastic models gave a difference between true and calculated volume measurements of not more than +/- 5%. In one hundred patients with aneurysms of different size and location the absolute volume of the aneurysm and its percentage of total left ventricular volume (V An %) were measured, and the statistical correlation with several hemodynamic and angiographic parameters was studied. Cardiac index (CI) and stroke volume (SV) appeared to decrease with increasing V An %, but with a correlation of no statistical significance. Left ventricular end-diastolic pressure (LVEDP) is raised with increasing V An %, but with a low statistical significance. Of angiographic parameters, end-diastolic volume (EDV) increased progressively and significantly with increasing V An %. This result is related to the extension of the noncontracting segment. Global ejection fraction (EF) decreased progressively with increasing enlargement of the aneurysm, in a statistically high correlation, and seemed to be the most sensitive index of total ventricular performance. Ejection fraction of the contractile portion (EFcp) was not related to V An % as involvement of large ventricular areas was consistent with preservation of contraction in unaffected regions. Evaluation of this parameter is suggested as a method of assessment for surgical treatment.

["Variant" angina: clinical, electrocardiographic and coronarographic aspects in 40 cases. Considerations for treatment (author's transl)]

Forty patients with chest pain and the electrocardiographic aspects of Prinzmetal's variant angina were studied by means of selective coronary arteriography. In 36 cases (90%) severe coronary lesions could be demonstrated: in 75% of the cases a critical obstruction involved a single major coronary trunk; only in 15% two or more vessels were affected. The vessel most frequently involved by critical obstruction was the left anterior descending (57%); in 5 cases (12.5%) a severe stenosis of the common left coronary trunk was present. In 8 cases critical stenosis were reduced by coronary dilators and were completely resolved in 2 cases. Peripheral lesions with multiple secondary branches involvement were present in none of the cases. A common finding was the absence of evident collateral anastomotic circulation. The comparison of the electrocardiographic manifestations of the anginal crisis and the angiographic findings showed a strict correlation between the area of subepicardial lesion and the major coronary vessel distributing to the corresponding myocardial region. Of the 40 patients, 17 were treated medically and 23 underwent a surgical aortocoronary bypass: the results (surgical mortality 22%; complete success 52%) are compared with those in the literature. Prognosis appears to be severe: coronary arteriography must be performed under criteria of urgency, and the possibilities of treatment must be considered on the basis of the angiographic findings.