Surgical exploration for penetrating neck trauma - an audit of results in 145 patients

BACKGROUND

Selective non-operative management (SNOM) is the current gold standard for the treatment of patients with penetrating neck trauma. The policy revolves around the liberal use of computed tomography angiography (CTA) in those patients who are haemodynamically stable, irrespective of the anatomical zone of injury, aiming at reducing the incidence of negative and non-therapeutic interventions and their potential complications.

METHODS

A retrospective audit of results of patients who underwent immediate surgical exploration at the Chris Hani Baragwanath Academic Hospital in Soweto between January 2010 and December 2015 was performed.

RESULTS

One-hundred and forty-five (145) patients, with a median age of 28 years (range 18-67 years), predominantly males (93.8%), underwent immediate exploration. Most injuries were caused by stab wounds (92.4%) and affected zone 2 (54.1%) on the left side of the neck (69.6%). The most common presentations were active haemorrhage (29.4%), shock (24.1%) and expanding haematoma (15.1%). A major vascular injury was found in 40%, and aero-digestive organ injury in 19.3%. The rate of negative-non-therapeutic exploration in this cohort was 4.1%. Complications were recorded in 7.6%, and the overall mortality was 9.6% secondary to early uncontrolled haemorrhage, sepsis and occlusive strokes.

CONCLUSIONS

The utilisation of SNOM with strict criteria for selection of patients who require immediate surgical exploration versus investigations with CTA results in a low rate of non-therapeutic interventions.

Surgical site infection after penetrating abdominal trauma with bowel involvement: a comparison between HIV-seropositive and seronegative patients

BACKGROUND

The influence of HIV-infection on surgical site infection (SSI) after surgery for penetrating abdominal trauma is not investigated and therefore not as yet elucidated. This prospective study was performed with the aim to compare the SSI rate in human immunodeficiency virus (HIV)-seropositive and HIV-negative patients and to identify other risk factors for this abdominal wound complication.

METHOD

98 patients who underwent small or large bowel resection and subsequent anastomosis due to penetrating abdominal trauma were included in the study. Injury related factors as well as demographical and physiological parameters, including HIV-status were analysed and superficial and deep SSI incidence rates were evaluated.

RESULTS

Of the 98 patients, 23 patients (23%) were HIV-seropositive. The overall superficial SSI rate was 45% and the deep SSI rate was 15%. No significant difference in SSI (superficial or deep) in the HIV-seropositive and -negative group was demonstrated (superficial SSI HIV-pos vs HIV-neg: 61% vs 40%; p=0.172, deep SSI 22% vs 13%, p=0.276). Multivariate analysis identified five independent risk factors for SSI: postoperative CD4 count < 250 cells/μl, postoperative albumin < 30 g/L, relook operation, anastomotic leak and colonic anastomosis.

CONCLUSION

HIV-infection is not an independent risk factor for developing SSI after penetrating abdominal trauma. Low postoperative CD4 count, irrespective of HIV status, low postoperative albumin, relook operation, anastomotic leak and colonic anastomosis are predictors for SSI irrespective of the HIV-serostatus. These factors should be considered in unison during the decision-making process of abdominal wound closure; planned secondary wound treatment or immediate application of negative pressure dressings in patients with a high-risk profile may decrease the hospital stay and the financial burden on the health care system.

[Update on gunshot wounds to extremities]

Due to recent rampage and terror attacks in Europe, gunshot wounds have become a focus of attention even though they are still rare in Europe. Approximately 50% of gunshot wounds affect the extremities and to understand the sequelae, a basic knowledge of wound ballistics is indispensable. The energy transmitted from the bullet to the tissue is responsible for the severity of the injury and is dependent on the type of weapon and ammunition. A differentiation is made between low-energy injuries caused, e.g. by pistols and high-energy injuries mostly caused by rifles. The higher energy transfer to the tissue in high-energy injuries, results in a temporary wound cavity in addition to the permanent wound channel with extensive soft tissue damage. High-energy gunshot fractures are also more extensive compared to those of low energy injuries. Debridement seems to be necessary for almost all gunshot wounds. Fractures should be temporarily stabilized with an external fixator due to contamination.

[Cardiac surgery in the elderly: perioperative care and operative strategies]

Caused by the age-dependent prevalence of cardiac diseases, the number of cardiac surgical interventions to geriatric patients is increasing. High life quality and life expectancy can be reached by cardiac operations. The advantage of cardiac surgical interventions is the decade's long positive effect. Accordingly also elderly benefit from complete revascularisation and from aortic valve replacement with biological prosthesis, which rarely degenerate in old age. A weak point is the surgical trauma, which can be reduced by less-invasive methods, such as OPCAB with aortic non-touch-technique, resulting in less than 1 % stroke. The indications for heart operations will be based on age-independent evidence-based guidelines. The decision for surgery is influenced by the expectation of the risk. This is defined by the co-morbidities and to lesser extent by the age per se. The operation risk can be calculated by risk-scores and hospital-specific data. The patient's expectations from the operation and his ability to overcome the accompanying stress must be thoroughly assessed. The operation must take place electively and at the right time. A good nutritional status and preoperative optimization of the organ functions are decisive for the prognosis. The blood-sugar-level must be optimized; thyroid function, (hidden) infections, anaemia and depression must be excluded or treated. The required screening tests should have been done already by the family doctor. The elderly are postoperatively susceptible to complications; especially low cardiac output, renal failure, respiratory insufficiency and stroke. Subsequently they need more intensive care.

[Abscess-forming and necrotizing aspergillus myocarditis in a surgical intensive care patient--a rare occurrence]

The case of an 89 year old patient is reported, in whom an aspergillus myocarditis was unexpectedly found at autopsy. Preoperatively, the patient showed no risk factors for an invasive mycosis. 5 days after uncomplicated surgery he developed septic shock due to peritonitis. After surgery and intensive care therapy the patient recovered initially. 23 days after the first operation the patient suddenly developed catecholamin-resistant myocardial failure and died. Ten days before, aspergillus spec. was found in a specimen of bronchial secretion. This finding was interpreted as colonisation and not treated.

[Acute myocardial infarction after blunt polytrauma -- successful coronary intervention]

Acute myocardial infarction following blunt chest trauma is a well reported but rare finding. Especially in severely injured patients the optimal therapy of the myocardial infarction is not well established, since anticoagulants, platelet aggregation inhibitors or thrombolytics are frequently contraindicated under these conditions. We report a case of a 41-year-old man, who presented with an acute myocardial infarction in combination with a severe polytrauma (multiple rib fractures, hematothorax, pelvic bone fractures, multiple injuries of intestinal organs) after a motorcycle accident with a blunt chest and abdominal trauma. After surgical treatment of the injuries of the bones and the intestinal organs a coronary angiography was immediately performed. The left anterior descending and the circumflex coronary artery were occluded in the mid-portion of the vessels. Coronary recanalization by PTCA and the implantation of coronary stents were successful in both vessels. Despite of a non-optimal blood flow after recanalization and stenting in one vessel (LAD TIMI II flow after recanalization), and a non-optimal accompanying medical therapy, during and after intervention (intravenous heparin starting 8 hours after the coronary intervention and platelet inhibitors starting 4 days after the intervention) the coronary angiogram after 2 months documented both vessels patent without a reocclusion or a restenosis. The case report documents, that in traumatic myocardial infarctions the treating of both, the attending injuries and the myocardial ischemia, is feasible. Early coronary angiography and coronary interventions, with or without stent-implantation, are indicated, even in cases in which an adequate accompanying medical therapy with heparin and platelet inhibitors is contraindicated.

[Acute myocardial infarct in pheochromocytoma crisis. Early coronary angiography findings and echocardiography follow-up]

A myocardial infarction is a rare complication of a pheochromocytoma. A pheochromo-cytoma crisis may occur spontaneously, during pregnancy, or may be induced by a local trauma of the tumor or by drugs. We present a case report of a 41-year-old woman without anamnestic episodes of hypertension or angina pectoris. During angiography of the mesenteric arteries for further diagnostics of a sonographically suspected liver tumor, she developed an acute pulmonary edema and a cardiogenic shock with the electro- and echocardiographic findings of a large anterolateral-apical-diaphragmal myocardial infarction. The immediate coronary angiography 90 min after the onset of the myocardial infarction showed normal coronary arteries with normal coronary blood flow of the arteries supplying myocardial areas with akinetic segments and those arteries supplying hyperkinetic segments. The blood catecholamine levels at this time were excessively elevated. The left ventricular function improved to almost normal within the next 4 weeks with the beginning of the improvement already before the abdominal tumor was surgically removed at day five. The histology documented a pheochromocytoma with acute necrosis. The early invasive findings support the hypothesis that a reversible spasm of several epicardial arteries and not a direct toxic effect of catecholamines could have been the cause of the small myocardial infarction and the observed large myocardial stunning.

[Blunt chest trauma with severe pulmonary contusion and traumatic myocardial infarction]

In the literature the incidence of cardiac involvement in blunt chest trauma varies considerably. This reflects the diagnostic problems encountered in polytraumatised patients. We report the case of an 18 year old man who suffered bilateral pulmonary contusion and traumatic myocardial infarction following a motorbike accident. The myocardial infarct was diagnosed by means of ECG, cardiac enzymes and echocardiography. When the diagnosis was made the time for successful interventional treatment had lapsed. A coronary angiography was performed after stabilisation which revealed a proximal dilatation of the left anterior descending artery. Left ventricular function was severely impaired (ejection fraction 26%). Due to the pulmonary contusion respiratory support was required for 14 days. The course was further complicated by left ventricular failure with low output.

Acute success rates of percutaneous transluminal coronary angioplasty in the treatment of chronic complete occlusions with use of the 0.014 magnum Meier wire

The 0.014 inch magnum Meier wire was used as the primary tool for recanalization of chronic total coronary artery occlusions in 230 consecutive patients treated by a single operator over a 3-year period. Exclusive use of the magnum wire resulted in an acute success rate of 80.9% in all occlusions and 64.7% in occlusions with a duration of >6 months. The complication rate of this procedure was extremely low with only one nontransmural myocardial infarction occurring. There were no vessel perforations, no in-hospital deaths, and no need for acute surgery. After failure to recanalize with the magnum wire, various other devices (conventional stiff guidewires, jagwire, crosswire) were used resulting in only six additional successful recanalizations but also in two vessel perforations with spontaneous closure of the perforation hole. Therefore, the 0.014-inch magnum Meier recanalization wire is highly effective for recanalization of chronic coronary artery occlusions, if used as the primary tool by an experienced operator, and is associated with an extremely low complication rate.

Combination of aneurysm and myocardial bridging at the same site of a coronary artery in a patient with obstructive hypertrophic cardiomyopathy

This case report describes the rare finding of myocardial bridging and a coronary aneurysm in the same coronary artery segment of a 57-year-old patient with obstructive hypertrophic cardiomyopathy. At the site of the aneurysm in the proximal LAD, the myocardial bridging resulted in an almost normal vessel diameter during systole with an aneurysmatic expansion of the vessel during diastole. This accidental finding does not necessarily require special therapy, since the underlying coronary aneurysm is small, with a low risk of thrombus formation or rupture, but it is big enough to prevent a coronary obstruction due to the myocardial bridging.

[Dissection of the sinus valsalvae aortae as a complication of coronary angioplasty]

The localized dissection of the aortic sinus of valsalvae is a rare complication of coronary angioplasty involving mainly the right coronary artery. In all previously published case reports (n = 10), a coronary dissection provided the entry door with subsequent retrograde progression of the dissection into the aortic root. In our case of a 75 year old female patient with symptomatic three vessel disease, a chronic occlusion of a proximal RCA could not be passed by a coronary guide wire. During the procedure an aneurysm of the aortic sinus occurred near the ostium of the RCA. The patient was referred for immediate aortocoronary bypass surgery. The inspection of the aortic sinus showed, as the entry of the dissection, a small puncture hole, adjacent to the ostium of the RCA, probably caused by the stiff 0.014 coronary guide wire, and no retrograde dissection of the right coronary artery. The localized dissection could easily be fixed by a prolene suture during the bypass surgery procedure with an uncomplicated postoperative course. If the entry of the dissection is within the coronary artery, forced contrast injections and balloon inflations promote its propagation and should be avoided. If the entry could be sealed by an intracoronary stent and the aneurysm remained localized, confirmed by echocardiographic controls, the aneurysm tends to resolve spontaneously in the first month without need for surgery. A progression of the aneurysm into the ascending aorta or a failure of an entry sealing with a stent is an indication for urgent surgical treatment.

[Comparison of the negative inotropic properties of nifedipine and nisoldipine using isovolumetric contractile parameters of the rat in vivo]

The vasoselectivity of new dihydropyridine calcium antagonists is much higher as compared to their prototype substance nifedipine. To investigate whether an equihypotensive dose of a new dihydropyridine has less negative inotropic properties in an intact circulation, nifedipine (NIF) and nisoldipine (NIS) were infused intravenously in an open-chest, anaesthetized rat model. The maximal isovolumic left ventricular pressure (LVPiso) and the maximal isovolumic rate of change of LV-pressure (dp/dtmaxiso) were determined to achieve load independent parameters of LV contractility. To evaluate the effect of the infused volume, the stability of the preparation and the hemodynamic effects of the drug-solvent, two groups with either infusion of isotonic NaCl-solution or 20% ethanol served as controls. NIF and NIS were infused in three equihypotensive doses within 7 min (NIF 250, 500, 1000 micrograms/kg; NIS 12.5, 25, 50 micrograms/kg). The decrease of the peripheral resistance of these doses was 74 +/- 6, 67 +/- 6, and 58 +/- 7% for NIF, and 78 +/- 7, 65 +/- 8, and 56 +/- 7% for NIS (p < 0.001 for all groups). In the control groups the afterload remained unchanged. NIF-infusion resulted in a dose-dependent decrease of LVPiso at the end of the infusion period (in percent of controls: NIF250 88 +/- 3%, p < 0.001; NIF500 74 +/- 3%, p < 0.001) as well as 15 min after the end of the infusion. In the same way dp/dtmaxiso decreased significantly after NIF at the end of infusion (NIF 250 82 +/- 6%, p < 0.001; NIF500 61 +/- 8%, p < 0.001) and 15 min after the end of the infusion. After NIS-infusion the contractility parameters decreased slightly after the higher dosage (25 micrograms/kg) at the end of the infusion period only (LVPiso 96 +/- 3%, p < 0.01; dp/dtmaxiso 93 +/- 5%, p < 0.01). There was no depressive effect on the isovolumic contractility parameters at the end of infusion of the lower dosage and 15 min after the drug-infusion of all dosages of NIS. Therefore, nisoldipine, as an example of a new dihydropyridine, has significantly less negative inotropic properties over a wide range of doses as compared to nifedipine in equihypotensive doses.

[Comparison of the cardiodepressive effects of nifedipine, isradipine, nisoldipine and felodipine in patients with coronary heart disease]

To compare the negative inotropic effects of the four dihydropyridine-calcium-channel-blockers nifedipine (NIF), isradipine (ISR), nisoldipine (NIS) and felodipine (FEL) in man, the drugs were infused within 30 min intravenously in an equihypotensive dosage (NIF 2 mg, ISR 0.5 mg, NIS 0.5 mg, FEL 0.6 mg; 10 patients in each group) in patients with coronary heart disease. As a control, an additional 10 patients received isotonic saline solution following an identical protocol. The afterload reduction was submaximal (reduction of peripheral resistance: NIF -23 +/- 9%, ISR -24 +/- 10%, NIS -28 +/- 6%, FEL -27 +/- 6%; no significant difference for group comparison) with a similar kinetic and a steady state of the afterload reduction after one-half of the infusion period to achieve a comparable sympathetic reflex activation. Preload parameters (PAP, LVEDP) were unchanged in all groups. A reflex tachycardia occurred in all treatment groups after 15 min of drug infusion. Due to its negative chronotropic properties, the reflex tachycardia was significantly attenuated after isradipine as compared to the other drugs (heart-rate changes: NIF +13 +/- 7%, p < 0.01; ISR +4 +/- 7%, not significant; NIS +20 +/- 10%, p < 0.01; FEL +17 +/- 12%, p < 0.01). Because of the baroreflex and sympathetic reflex activation the left-ventricular dp/dtmax increased after isradipine (+14 +/- 10%, p < 0.01) and nisoldipine (+16 +/- 13%, p < 0.01). The lack of a significant dp/dtmax increase in spite of a comparable afterload reduction after felodipine (+5 +/- 8%, not significant) or nifedipine (-3 +/- 6%, not significant) must be a consequence of the cardiodepressive properties of these drugs. Therefore, in an equihypotensive dosage, the strongest negative inotropic effects were observed after nifedipine, lesser effects after felodipine (p < 0.03), and the weakest cardiodepressive effects after isradipine (p < 0.01) and nisoldipine (p < 0.01). For clinical applications the lesser cardiodepressive properties of the new dihydropyridine-derivatives should be advantageous in patients with already reduced left-ventricular performance or for use in combination with other negative inotropic drugs, e.g., betablockers.

[Acute and long-term results of coronary Excimer laser angioplasty]

Laser and catheter technology have been considerably improved within the first 2 years of the clinical use of coronary excimer laser angioplasty. Furthermore, patient selection has changed due to increasing operator experience. We report on the acute- and long-term results achieved in 163 patients in three subgroups with different system parameters and catheter technology. In the initial series 1 (N:60) a prototype catheter with a diameter of 1.4 mm was used. In series 2 and 3, we employed improved transmission devices with 1.3, 1.5 or 1.8 mm. In series 3 the pulsewidth was increased from 60 ns to 115 ns. The target vessel was the LAD in 68%, the LCX in 10%, and the RCA in 21%. According to the AHA/ACC Lesion classification there were 13% type A, 26% type B1, 55% type B2, and 5% type C lesions. Stand-alone laser angioplasty was performed in 23/60 (38%), 24/40 (60%), and 34/64 (53%) in series 1, 2, and 3, respectively. Additional balloon angioplasty was necessary in 32, 11, and 21 interventions. Failure of laser angioplasty occurred in five patients of series 1 and 2, and nine patients of series 3. Frequently observed complications included coronary spasm in 18 to 32%, dissections in 16% to 33%, and vessel closure in 18 to 27%. Myocardial infarction occurred in three patients in the first and one patient of the second and third series. There was one in-hospital death in series 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Success rate and incidence of restenosis following coronary excimer laser angioplasty: results of a single center experience

The initial single center experience of percutaneous coronary excimer laser angioplasty is described for the first three series of 147 patients. Sixty patients were treated with a prototype 1.4-mm laser catheter, 40 patients with improved transmission devices, and the third series of 47 patients with an increased pulse width of the laser system allowing improved energy transmission. In 17 patients (12%) laser angioplasty could not be initiated due to inability to cross the lesion with the guidewire or to place the catheter coaxially within the vessel. In 32 patients (58%) of series 1, 11 patients (31%) of series 2, and 17 patients (43%) of series 3, additional balloon dilatation following laser treatment was necessary due to vessel closure (24%) or due to an insufficient angiographic result (35%). There was one death in series 1 (2%) and 2 (3%) each, one perforation in series 2 (3%), two transmural myocardial infarctions in series 1 (4%), and one myocardial infarction in series 2 (3%). During the 6-month follow-up period one patient in series 2 (2%), and one patient in series 3 (3%) died. Angiographic restenosis was found in 22, 12, and 11 patients of series 1 (40%), 2 (34%), and 3 (27%), respectively. No patient developed a transmural myocardial infarction. Thus, percutaneous coronary excimer laser angioplasty can be performed as a safe and feasible procedure in patients with coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of heart rate on transmitral flow velocity profile and Doppler measurements of mitral valve area in patients with mitral stenosis

To study the effect of heart rate changes on Doppler measurements of mitral valve area atrial pacing was performed in 14 patients with mitral stenosis and sinus rhythm. Continuous wave Doppler and haemodynamic measurements were performed simultaneously at rest and during pacing-induced tachycardia. (1) Mitral valve area was determined using the conventional pressure half time method. (2) Additionally, mitral valve area was calculated with a combined Doppler and thermodilution technique according to the continuity equation. (3) Simultaneous invasive measurements were used for calculation of the mitral valve area according to the Gorlin formula. With increasing heart rate (69 +/- 13-97 +/- 15-114 +/- 13 beats min-1) mitral valve area either determined by the continuity equation (1.0 +/- 0.2-1.0 +/- 0.3-1.1 +/- 0.4 cm2) or the Gorlin formula (1.2 +/- 0.3-1.2 +/- 0.4-1.3 +/- 0.4 cm2) remained constant. Both methods correlated closely not only at rest (r = 0.88, SEE = 0.11 cm2, P less than 0.001), but also during atrial pacing (first level: r = 0.95, SEE = 0.10 cm2, P less than 0.001, second level: r = 0.95, SEE = 0.13 cm2, P less than 0.001). In contrast, mitral valve area calculated according to the pressure half time method increased significantly during atrial pacing (1.0 +/- 0.3-1.8 +/- 0.5-2.0 +/- 0.5 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Value of a modified continuity equation method to quantify mitral valve area in patients with mitral stenosis and sinus rhythm

To quantify valve area in mitral stenosis, a modified continuity equation method using continuous wave Doppler and thermodilution measurements was applied. In 14 patients with mitral stenosis and sinus rhythm (age: 49 +/- 11 years), transmitral flow velocity was recorded by continuous wave Doppler during right and left heart catheterization. Mitral valve area was calculated by three different methods: 1. According to the continuity equation, stroke volume (thermodilution technique) was divided by the registered time velocity integral of the mitral stenotic jet (continuous wave Doppler). 2. Mitral valve area was calculated by the pressure half-time method. 3. Simultaneous pulmonary capillary wedge and left ventricular pressure measurements were used for determination of mitral valve area according to the Gorlin formula. The mitral valve area determined by application of the continuity equation (y) showed a close correlation to the valve area calculated by the Gorlin equation (x): y = 0.73x + 0.12, SEE = 0.11 cm2, r = 0.88, P less than 0.001. In contrast, the correlation between mitral valve area determined by pressure half-time (y) and the Gorlin formula (x) was not as good: y = 0.77x + 0.11, SEE = 0.26 cm2, r = 0.65, P less than 0.05. Thus, the continuity equation method using combined continuous wave Doppler and thermodilution technique allows a valid determination of mitral valve area. In patients with mitral stenosis and sinus rhythm, this technique is superior to the noninvasive determination of mitral valve area by the conventional pressure half-time method.

Intraoperative valvuloplasty in calcific aortic stenosis: a study comparing the mechanism of a novel expandable device with conventional balloon dilatation

In selected patients with calcific aortic stenosis, balloon valvuloplasty is an intermediate alternative to surgery. The effect of balloon valvuloplasty to increase valve area, however, is limited and the restenosis rate is high during follow-up. To improve the results and reduce the complication rate, a new device for valvuloplasty of calcific aortic stenosis was developed. This system consists of three expandable prongs mounted on a freely movable catheter tip. To evaluate the efficacy of this new device, valvuloplasty was performed in 10 patients with severe aortic stenosis intraoperatively just prior to valve replacement. Comparison was made with the results of conventional balloon dilatation performed in an additional 20 patients during surgery. Using the new device, the relative orifice area increased from 10 +/- 3% before to 20 +/- 6% following intervention. However, in only one patient was a considerable increase of static valve area (greater than 15%) found. The results were comparable to the effect of conventional balloon dilatation, which led to an increase of orifice area from 12 +/- 7% to 24 +/- 10%. With both systems, the best results were achieved in patients with aortic stenosis and significant commissural fusion. In contrast, in bicuspid or tricuspid valves without fused commissures the effect of the intervention was limited. Because complete obstruction of the aortic valve does not occur during dilatation, this new device might be superior to conventional balloon dilatation. Preselection of patients according to the morphology of the valve seems mandatory to improve the success and reduce the complication rate of valvuloplasty in aortic stenosis.

Effects of intracoronary nitroglycerin on lumen diameter during early follow-up angiography after coronary excimer laser atherectomy

The incidence of coronary vasospasm during and following excimer laser atherectomy is considerable. The aim of this study was to investigate vasoconstriction of the target vessel during early follow-up angiography. In 50 patients an angiogram was performed 24 hours after intervention. Nineteen patients were treated with stand-alone laser atherectomy (group I), another 19 with laser and additional balloon angioplasty (group II) and 12 with balloon angioplasty alone (group III). Lumen diameter and percent stenosis before and after intracoronary application of 0.1 mg nitroglycerin were determined. The differences were compared between groups I, II and III, and for patients with (N = 14) and without (N = 24) vasospasm during laser atherectomy. There was a significant increase in lumen diameter, of 0.17 +/- 0.28 mm, after nitroglycerin in group I, of 0.18 +/- 0.29 mm in group II (P = 0.02) and of 0.03 +/- 0.21 mm in group III (ns). In patients with vasospasm during laser atherectomy the average increase in lumen diameter was 0.28 +/- 0.24 mm (P less than 0.01), and in patients without vasospasm 0.12 +/- 0.29 mm (P = 0.09). We conclude that one day after coronary excimer laser atherectomy intracoronary nitroglycerin significantly affects lumen diameter at the site of previous stenosis, an effect undetectable after balloon angioplasty. Thus, vasoconstriction after excimer laser ablation seems to be a common phenomenon and is prolonged in patients with vasospasm during the previous intervention.

[Effect of acute short-term ischemia during PTCA on the function of the right ventricle]

To determine whether a transient ischemia of the right ventricle leads to right ventricular impairment and whether RV function can also be influenced by septal ischemia caused by an occlusion of the left anterior descending coronary artery (LAD), RV function before and at the end of 60 s of ischemia during PTCA was assessed in 15 patients with single-vessel disease of either the right coronary artery (RCA, n = 10) or the LAD (n = 5). The RV-enddiastolic pressure and the pulmonary capillary wedge pressure (PCW) were recorded continuously. The RV ejection fraction was determined from ventriculograms performed before and during coronary occlusion. An increase of RVEDP from 3.7 +/- 1.2 to 8.3 +/- 1.8 mm Hg (p less than or equal to 0.001) and a decrease of the RV-ejection fraction from 52 +/- 3 to 33 +/- 8% (p less than or equal to 0.001) occurred during RCA occlusion with a predominant ischemia of the RV free wall only, and not during LAD occlusion with left ventricular and septal ischemia. The extent of the RV dysfunction was independent of an additional increase of RV afterload (PCW increase). Comparable to ischemic effects on left ventricular function, an acute right ventricular myocardial ischemia results in a severe RV contractile failure.

[Occluding spasm of the total left coronary artery during coronary angiography]

Catheter-induced coronary artery spasms are rare during diagnostic coronary angiography, and they occur more often after PTCA because of local vessel wall injury. These spasms are rapidly reversible after administration of nitroglycerine and are normally no cause of serious complications. We report about a catheter-induced occlusive spasm of the entire left anterior descending and circumflex coronary artery in a 56-year-old patient with coronary double-vessel disease, 70% restenosis of the LAD, and a history of two coronary angiographic procedures and one PTCA without any complication. The spasm occurred immediately after the intubation of the left main stem with a 9F PTCA guiding catheter before the coronary guide wire or balloon was advanced into the LAD. Cardiac resuscitation was necessary due to acute left heart failure. The spasm was spontaneously reversible, but reproducible. Therefore, life-threatening coronary artery spasm can occur during coronary angiography or PTCA, but the tendency of spontaneous spasm relief seems to be high.

[Percutaneous coronary excimer laser angioplasty]

Available preliminary clinical studies have shown that ablation of atherosclerotic plaques can be achieved by means of pulsed excimer laser coronary angioplasty via flexible energy transmission systems. The goal of current studies using improved catheter technology is to enhance the acute success rate since, based on initial studies, it can be assumed that only about 40 to 45% of the patients can be successfully treated. The on-going investigations were carried out primarily with three different excimer laser systems which employ a wavelength of 308 nm but differing pulse widths and transmission systems. In the first American multicenter study by Litvack and Margolis a catheter system was used with a pulse width of 180 to 220 ns. The fibers have a shaft diameter of 100 microns with a conically-thickened distal end measuring 200 microns, the ablative area encompasses 35 to 45% of the total catheter tip surface. The excimer laser used in the second American multicenter study by Sanborn and Isner has a pulse width of 120 ns. This catheter is relatively unflexible due to the 200 microns fiber diameter. The ablative catheter tip area is 25 to 30%. In Tübingen a system was used with a pulse width of 60 ns. The energy is transmitted through fibers with a diameter of 100 microns. The effective ablative area in the first series of patients was about 15%, in the second series about 25 to 30%. At present, the energy density of all three systems is comparable with at least 25 to 35 mJ/mm2. Since there is currently no means for accurate assessment, the question of whether a shorter pulse width of comparable energy density is more effective than the longer pulse width, remains an open issue. The flexibility of the systems used by Margolis and in Tübingen enable ablation not only of proximal, but also arteriosclerotic plaques located in the middle-third of vessels. The flexibility and steerability, however, are inferior to balloon catheter systems. In the study carried out by Litvack and Margolis, in which more than 600 patients have been treated, and the results from 514 patients reported, there was no patient selection in the first series. The study by Sanborn and Isner included 88 patients. Due to the relatively unflexible catheter system, only those patients were treated who had proximal stenosis of the left anterior descending or right coronary artery or marginal branches of the circumflex artery without marked tortuosity.(ABSTRACT TRUNCATED AT 400 WORDS)

[Percutaneous coronary Excimer laser angioplasty in patients with coronary heart disease]

To verify the efficacy and safety of percutaneous coronary excimer laser angioplasty in patients with coronary artery disease a prospective study was conducted in 60 patients. The application of laser light was possible in 55 of the 60 patients. A novel 1.4-mm diameter catheter with 20 quartz fibers of 100-microns diameter, each arranged concentrically around a central lumen suitable for an 0.014-inch flexible guide wire was used. The light source was a commercial excimer laser emitting energy at a wavelength of 308 nm, with a pulse duration of 60 ns. The laser was operated at 20 Hz; mean energy transmission was 30 +/- 5 mJ/mm2. In 23 of the 55 patients treated with excimer laser energy the qualitative angiographic results were sufficient. In 32 patients additional balloon angioplasty was necessary, either because of an insufficient result or due to vessel closure after laser ablation. In 47 of the 55 patients control angiography was performed within the 6-month follow-up period. Rate of restenosis was higher in patients treated with laser ablation and subsequent balloon angioplasty (16 of 28) than in patients treated with laser ablation alone (6 of 19). Results of the 6-month observation period suggest that 1) coronary excimer laser angioplasty in combination with subsequent balloon angioplasty results in a considerable increase of the restenosis rate; 2) the exclusive use of laser ablation also results in a restenosis rate comparable to balloon angioplasty alone; and 3) the impact of this new method using improved application systems and higher energy transmission has to be determined in further studies.

Percutaneous coronary excimer laser angioplasty in patients with stable and unstable angina pectoris. Acute results and incidence of restenosis during 6-month follow-up

A clinical study was conducted to evaluate the efficacy and safety of percutaneous coronary excimer laser angioplasty in 60 patients with coronary artery disease. Forty-nine patients had stable exertional angina, and 11 patients had unstable angina despite medical therapy. A novel 1.4-mm diameter catheter with 20 quartz fibers of 100-microns diameter each arranged concentrically around a central lumen suitable for a 0.014-in. flexible guide wire was coupled to an excimer laser. A commercial excimer laser emitting energy at a wavelength of 308 nm with a pulse duration of 60 nsec was used. The laser was operated at 20 Hz. Mean energy transmission was 30 +/- 5 mJ/mm2. In five of the 60 patients, laser angioplasty was not attempted. In 23 patients with laser ablation alone, percent stenosis decreased from 76 +/- 14% before to 27 +/- 17% after ablation and was 34 +/- 15% at the early follow-up angiogram. In 32 patients, additional balloon angioplasty was performed because of vessel closure after laser ablation in 11 and an insufficient qualitative result in 21 patients. Of the 11 patients with unstable angina, one patient died due to vessel closure 3 hours after intervention, and two patients developed a myocardial infarction. In 22 of 47 patients with late follow-up angiography, restenosis within the 6-month follow-up period occurred. Rate of restenosis was higher in patients treated with laser ablation and balloon angioplasty (16 of 28) than in patients treated with laser ablation alone (six of 19). These results suggest that coronary excimer laser angioplasty for ablation of obstructive lesions is feasible and safe in patients with stable angina. However, development of new catheter systems is necessary for an improved success rate.

[Electrophysiologic effects of the calcium antagonist isradipine, a double-blind placebo controlled study]

The electrophysiologic effects of the calcium channel antagonist isradipine (0.5 mg) in comparison to placebo were evaluated in a double blind study with nine patients in two groups. The patient groups were not different in respect to the underlying cardiac disease, electrophysiologic parameters at the baseline study, or in blood pressure. Isradipine significantly decreased the systolic (p less than 0.01) and diastolic (p less than 0.05) blood pressure, while sinus cycle length decreased significantly (p less than 0.05) in the placebo group and the isradipine group with no difference between the two study groups. The influence on sinus node recovery time, effective refractory period of the av-node, intranodal conduction time, and PR interval were not significant. In conclusion, isradipine significantly decreased systolic and diastolic blood pressure. The decrease in sinus cycle length after intravenous isradipine was not significantly different from the decrease seen in the placebo group. Atrioventricular conduction was not significantly affected.

[Myocardial effects of the calcium antagonists nifedipine, nisoldipine and isradipine in coronary heart disease]

Cardiac and peripheral effects of three calcium antagonists of the dihydropyridine group were compared in three groups of ten men each with coronary heart disease (mean age 56 +/- 6 years). Dosages (by 30 minutes intravenous infusions) were: 2 mg nifedipine in group I, 0.5 mg nisoldipine in group II and 0.5 mg isradipine in group III. In this dosage peripheral effects--decrease of peripheral vascular resistance and mean aortic pressure--did not differ significantly between them. As a consequence of different negative chronotropic properties the extent of the observed reflex tachycardia was different: there was no significant heart rate increase after isradipine, an increase by 9.8% (P less than or equal to 0.001) after nifedipine and by 20.4% (P less than or equal to 0.001) after nisoldipine. Left-ventricular pressure-rise velocity as a parameter of myocardial contractility rose by 15.3% in group II (P less than or equal to 0.001) and by 13.5% in group III (p less than or equal to 0.001), but not in group I. These data show, that peripheral equipotent dosages of the three calcium antagonists can have different myocardial effects.

Myocardial and coronary effects of captopril during pacing-induced ischaemia in patients with coronary artery disease

It has been speculated that ACE inhibitors may have beneficial effects in patients with coronary artery disease not only by their vasodilator properties but also by an effect on an assumed local renin-angiotensin system in atherosclerotic coronary arteries. Thus, the aim of the present study was to evaluate the effect of a single intravenous infusion of captopril on haemodynamics and coronary diameter at rest and during myocardial ischaemia induced by rapid atrial pacing. The study was performed in 12 patients with coronary artery disease and exertional angina pectoris despite medical therapy. Central haemodynamics (PAO, PAP) and left ventricular end-diastolic pressure were measured. Biplane cineventriculography and coronary arteriography were performed during control pacing (10% above the normal heart rate) before and after 15 min of captopril infusion, as well as during angina pectoris induced by rapid atrial pacing before and after captopril (six patients 0.15 mg kg-1, six patients 0.3 mg kg-1). Mean aortic pressure was not significantly decreased by either 0.15 mg kg-1 or 0.3 mg kg-1, whereas mean pulmonary pressure was significantly reduced by captopril by 28% at rest and 34% during rapid atrial pacing. Neither the endsystolic volume index nor left ventricular ejection fraction was significantly affected by captopril. Left ventricular end-diastolic volume index was reduced by 9% at rest and 7% during pacing-induced angina. Left ventricular end-diastolic pressure decreased from 11 +/- 9 mmHg to 4.8 +/- 4.1 mmHg at rest after captopril, and from 10 +/- 11 mmHg to 5.1 +/- 5.0 mmHg during pacing-induced angina after captopril.(ABSTRACT TRUNCATED AT 250 WORDS)

Initial angiographic results in ablation of atherosclerotic plaque by percutaneous coronary excimer laser angioplasty without subsequent balloon dilatation

Percutaneous transluminal coronary excimer laser angioplasty was performed in 15 patients using a 1.3-mm diameter laser catheter. The catheter consists of 20 concentric quartz fibers of 100 microns diameter each located around a central lumen suitable for a 0.014-inch flexible guidewire. The catheter was coupled to an excimer laser delivering energy at a wavelength of 308 nm and at a pulsewidth of 60 ns. Quantitative analysis of the angiograms documented a decrease from 77 +/- 15% diameter stenosis before intervention to 40 +/- 22% after the first irradiation cycle and to 21 +/- 17% after termination of laser ablation. The minimal lumen diameter increased from 0.4 +/- 0.2 to 1.3 +/- 0.4 and to 1.6 +/- 0.4 mm, respectively. Vessel reocclusion was seen in 2 patients at 24-hour control angiography. No procedure-related major complications such as vessel perforation occurred. In 8 patients, however, intraluminal lucencies were seen, which were persistently visualized 24 hours after intervention in 6 patients. Despite pretreatment with intracoronary nitroglycerin, coronary spasm occurred in 8 patients and was reversible after additional sublingual vasodilator therapy. The results of this pilot study suggest that percutaneous coronary excimer laser angioplasty is feasible and effective for ablation of coronary lesions in selected patients and can be performed without subsequent conventional balloon angioplasty. The clinical impact of this new interventional technique, however, remains to be assessed.

[The acute hemodynamic effects of the new vasodilating beta blocker carvedilol in comparison with combined administration of nifedipine and propranolol in patients with coronary heart disease]

The acute hemodynamic effects of carvedilol, a new vasodilating betablocker, were assessed in comparison to the response to nifedipine or a combination of nifedipine and propranolol in patients with coronary artery disease. Either 5 mg carvedilol, 2 mg nifedipine or 2 mg nifedipine + 5 mg propranolol (N + P) were administered intravenously in a not randomized study within 30 min to 10 patients for each drug. Carvedilol reduced (comparable to the effect of N + P) the left ventricular afterload with a decrease of AOPm of 12.6%, p less than 0.001 (N + P -11.8%, p less than 0.001) and systemic vascular resistance of 9.1%, p less than 0.02 (N + P -10.0%, p less than 0.01) and no change of cardiac index. Single treatment with nifedipine leads to a reflex increase of heart rate which could not be observed after carvedilol or N + P as a result of the betablocking properties of carvedilol and propranolol. Therefore, the rate-pressure-product at rest was unchanged after nifedipine but decreased significantly after carvedilol (-10.9%, p less than 0.01) and N + P (-12.4%, p less than 0.01). Negative inotropic effects were significantly lower after carvedilol, with a 6.3% (p less than 0.05) decrease of LV dP/dtmax, compared to N + P (-12.0%, p less than 0.01). Since preload, afterload, and heart rate changes were equal in both groups negative inotropic effects can be compared on the base of dP/dtmax changes. The acute hemodynamic effects (vasodilation without reflex tachycardia, negative inotropic effects) of the new vasodilating betablocker carvedilol are comparable to a combined treatment with nifedipine and propranolol in patients with coronary artery disease and well preserved left ventricular global function.

Percutaneous coronary excimer laser angioplasty: initial clinical results

A novel 1.3 mm diameter laser catheter, consisting of 20 concentric 100 microns quartz fibres around a central lumen for a 0.35 mm flexible guide wire, was used to ablate atherosclerotic tissue in thirty patients with coronary artery disease. The laser catheter was coupled to an excimer laser delivering energy at a wavelength of 308 nm and a pulsewidth of 60 ns. The primary success rate was 90% (27 of 30 lesions). The mean (SD) percentage stenosis fell from 85 (15)% to 41 (19)% after laser ablation. In ten patients the lumen diameter after laser angioplasty was considered sufficient, but subsequent balloon angioplasty was carried out for the other twenty patients. Failure to pass the lesion was caused by vessel kinking in two patients and a total occlusion in one patient. No complications directly attributable to laser ablation, such as vessel wall perforation, occurred; one dissection occurred but had no clinical sequelae. There was one early reocclusion and death in a patient with triple vessel disease and unstable angina, probably as a result of plaque rupture after balloon angioplasty. These results are encouraging and justify further clinical investigations.

[Percutaneous transluminal excimer laser coronary angioplasty]

Percutaneous transluminal laser coronary angioplasty (PTLCA) was undertaken in five patients (four men and one woman, aged 44-72 years) with coronary artery stenosis. The vessel diameter was increased in all patients after PTLCA; complete ablation of the atheromatous plaque succeeded in three. In the other two the catheter could not be advanced across the entire stenotic region. After PTLCA the stenoses were 40-50% of normal lumen. Balloon dilatation was additionally done in all five patients. In three this caused dissection of the vessel wall distal to the stenosis and possible intracoronary thrombus formation: this would suggest that balloon dilatation after laser angioplasty is not recommendable. PTLCA widens the spectrum of invasive methods for treating coronary artery stenosis.

Validation of continuous-wave Doppler measurements of mitral valve gradients during exercise--a simultaneous Doppler-catheter study

In patients with mitral stenosis, continuous-wave Doppler measurements of the maximal transmitral inflow velocity can be converted into transvalvular pressure gradients using the modified Bernoulli equation. Because of close correlations between Doppler- and catheter-measured gradients this method has become a valuable tool in non-invasive evaluation of mitral stenosis at rest. However, in some patients, exercise studies are necessary to determine the haemodynamic significance of the valve stenosis. The accuracy of continuous-wave Doppler in this setting has not yet been validated. Thus, in 20 selected patients with pure or predominant mitral stenosis, continuous-wave Doppler echocardiography was performed during left- and right-heart catheterization. At rest and during submaximal bicycle exercise, Doppler and pressure measurements were simultaneously performed. The Doppler gradient was calculated according to the modified Bernoulli equation while the mean manometric gradient was determined from the simultaneous pulmonary wedge and left ventricular pressure curves. Exercise caused a significant increase of cardiac output (4.8 +/- 1.3 to 5.7 +/- 1.31 min-1) and heart rate (59.7 +/- 12.0 to 95.3 +/- 14.3 beats min-1). The mean Doppler gradient increased from 6.8 +/- 2.1 to 12.2 +/- 3.2 mmHg. The manometric gradient showed a comparable increase of 9.5 +/- 2.4 to 17.2 +/- 3.7 mmHg, respectively. Correlation between Doppler and manometric data was close (y = 0.79x-0.67,r = 0.90,SEE = 0.97 mmHg) at rest and still good during exercise (y = 0.71x-0.10,r = 0.82,SEE = 1.97 mmHg). Thus, in some patients with borderline resting gradients and valve areas, exercise Doppler might allow further identification of the haemodynamic severity of mitral stenosis.

[Success and complication rates of coronary angioplasty in the unstable angina pectoris stage after myocardial infarct--a comparison with percutaneous transluminal coronary angioplasty in the acute infarct stage and unstable angina pectoris without preceding myocardial infarct]

To evaluate whether there is a difference in terms of the success and complication rates of PTCA in patients (pts) with unstable angina pectoris (UAP) after myocardial infarction (group I) and patients with myocardial infarction (group II), as well as in patients with UAP without preceding myocardial infarction (group III), we analyzed the data of 188 patients retrospectively. Acute PTCA was performed in 42 patients of group I, 55 patients of group II, and 91 patients of group III. The primary success rate was comparable in all three groups (group I: 74%; group II: 76%; group III: 77%). The incidence of acute ACVB operation was comparable in group I (5 pts: 9%) and group III (10 pts: 11%). One patient was operated during an acute myocardial infarction. Five patients of group I (9%) and seven patients of group III (8%) developed a myocardial infarction. Three patients of group I (7%) and three patients of group II (5%) died during hospitalization. PTCA performed during acute myocardial ischemia has the highest complication rate in patients with UAP after myocardial infarction and is considerably higher than in patients with UAP without preceding infarction.

Myocardial properties of the new dihydropyridine calcium antagonist isradipine compared to nifedipine with or without additional beta blockade in coronary artery disease

Isradipine is a new dihydropyridine calcium antagonist with myocardial effects significantly different from those of nifedipine, as shown by in vitro and animal experimental data. Isradipine selectively inhibits the sinus node but not the atrioventricular conduction and its negative inotropic action is much less if administered in a dose of comparable peripheral effects. To study these effects in man, 40 patients with coronary artery disease were divided into 2 groups receiving either a continuous 30-minute intravenous infusion of 2 mg of nifedipine or 0.5 mg of isradipine, doses that resulted in a comparable afterload reduction (decrease of systemic vascular resistance: nifedipine -22.1%, isradipine -25%, p less than 0.001). Ten patients in each group received an additional intravenous bolus of 5 mg of propranolol at the end of the calcium antagonist administration to antagonize its induced adrenergic reflex mechanisms. The heart rate significantly increased after nifedipine only (+9.2%, p less than 0.001), experienced no change after isradipine and the nifedipine and propranolol combination and decreased after the combination of isradipine and propranolol (-9.6%, p less than 0.001). This resulted in a significant decrease of the rate pressure product with isradipine (-12.5%, p less than 0.001) but not with nifedipine. As a result of the afterload-induced adrenergic reflex mechanisms, the maximal derivative of the left ventricular pressure increased after isradipine administration (+13.5%, p less than 0.001) and was unchanged after nifedipine, which demonstrates the significantly less negative inotropic properties of isradipine as compared with nifedipine.

[Interobserver comparison of quantitative analysis of local wall function of the left ventricle in stress cineventriculography]

During diagnostic heart catheterization biplane cineventriculograms of 46 patients at rest and directly after bicycle ergometry (72.8 +/- 27.8 W) were performed. The aim of the study was to determine the value of local wall motion analysis under physical exercise. Therefore two observers independently analyzed global and local left ventricular parameters. 38 patients had coronary artery disease, 23 with a history of myocardial infarction. Enddiastolic (EDV) and endsystolic volume (ESV) were evaluated and ejection fraction (EF) was calculated. Local wall motion was analyzed using a radial model with 60 radii in the 30 degrees RAO- and 60 degrees LAO-Projektion. A systolic segmental shortening was determined for the anterobasal (AB), anterolateral (AL), apical (AP), diaphragmatic (DP), posterobasal (PB) (30 degrees-RAO), septal (SE) and posterolateral (PL) area (60 degrees-LAO). Global functional parameters (EDV, ESV, EF) revealed good correlations between both observers with correlation coefficients (r) varying from 0.83 to 0.92. Local wall motion had sufficient correlations (r) at rest and during exercise (data in brackets) in the RAO-projektion: AB: 0.88 (0.73), AL: 0.69 (0.72), AP: 0.82 (0.78), DP: 0.77 (0.75), PB: 0.78 (0.78) and in the septal segment (LAO-projection): 0.69 (0.71). Less sufficient correlations were found in the posterolateral segment (LAO, especially at rest: 0.50 (0.69). Thus, global ventricular parameters can be determined at rest and during exercise independently of the observer. Local wall motion, too, can be quantified with sufficient accuracy with exception of the posterolateral area in the LAO-projektion.

[Anterior wall infarct in an angiographically demonstrated muscle bridge of the ramus interventricularis anterior]

Coronary angiography in a 58-year-old man who had sustained an anterior-wall myocardial infarction demonstrated a myocardial bridge over the anterior interventricular branch as the only abnormal finding which, in the absence of any arteriosclerotic changes proximal or at the level of the bridge, suggests a causal relationship.

[Anterior wall infarct in an 18-year-old patient with Hodgkin's disease. Possible relation between mediastinal irradiation, accelerated arteriosclerosis and vincristine chemotherapy]

An 18-year-old male patient with Hodgkin's disease, having undergone radiotherapy to the mediastinum two-and-a-half years previously, developed symptoms of an acute myocardial infarction within three hours of a vincristine injection (the first course of vincristine chemotherapy had been finished eight days previously). Invasive investigation after three weeks revealed single-vessel occlusion of the anterior interventricular branch with an anterior-wall aneurysm. The most likely cause of the coronary heart disease in this patient is changes in the anterior interventricular branch resulting from the mediastinal radiotherapy. The infarct itself occurred in close temporal relationship to the vincristine injection, which in several case reports has been implicated in the triggering of coronary spasms.

[Effect of rapid atrial pacing on left ventricular ejection fraction in patients without organic heart disease]

Pacing-induced decrease of left ventricular ejection fraction (LVEF) in patients with coronary artery disease has been proposed as a sign of myocardial ischemia, whereas a slight increase or no change is speculated to be the normal response to rapid atrial pacing. The studies of the pacing-induced effects in normals, however, are of limited value, because of either inhomogeneous patient population or different, mainly non-invasive, methods for determination of LVEF. It was therefore the aim of the present study to assess the pacing-induced changes of left ventricular ejection fraction in a homogeneous group of patients. In 10 patients (mean age: 48 +/- 2 years) with normal coronary arteriograms and normal LV-function at rest, rapid atrial pacing was performed stepwise to a maximal pacing rate of 150 beats per minute. In all patients left ventricular end-diastolic pressure LVEDP and time constant of relaxation period tau decreased, while the parameter of contractility Max Dp/dt increased due to increase in heart rate. Furthermore, there was no limited coronary reserve or myocardial lactate production during atrial stimulation as a sign of pacing-induced ischemia. In all patients biplane ventriculography was performed at rest and during maximal stimulation. While end-diastolic volume index EDVI decreased in every patient (71 +/- 5----42 +/- 4 ml/m2, p less than 0.005) and systolic volume index did not change (17 +/- 2----14 +/- 2 ml/m2, N.S.), there was a significant decrease of ejection fraction from 75 +/- 2 to 66 +/- 3% (p less than 0.005). Basal heart rate, age, sex or basal ejection fraction did not influence the response of ejection fraction to rapid atrial pacing. Even after drug-induce afterload reduction there was a significant pacing induced decrease of ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Percutaneous transluminal coronary angioplasty and aortocoronary bypass surgery in unstable angina pectoris and coronary multivessel disease]

In 113 patients demonstrating the clinical syndrome of unstable angina, acute-stage coronary angiography revealed multivessel disease. Acute PTCA of the ischaemia-related coronary artery or bypass grafting was performed depending on angiographic criteria. Of the total of 68 patients in whom PTCA was performed, 45 had two-vessel disease (2 vd) and 23 three-vessel disease (3 vd). 12 of the 45 patients with bypass operation had a left main stem stenosis, whereas 33 had three-vessel disease. The primary success rate of PTCA was 81%, 89% in patients with 2 vd and 70% in patients with 3 vd. Acute post-PTCA bypass grafting was necessary in 2 patients having 2 vd and in 5 patients suffering from 3 vd. 5 of the 68 patients treated with PTCA developed a transmural myocardial infarct and one patient died after PTCA and emergency bypass surgery. 8 of the 45 operated patients had a perioperative or postoperative myocardial infarct and 5 patients died intraoperatively or postoperatively. The overall morbidity was 11.5%, and the mortality of hospitalised patients was 5.3% (6/113). Combination of PTCA with emergency bypass grafting offers a new and effective treatment with an acceptable risk even in multivessel disease patients and in those having unstable angina pectoris. The additional use of PTCA definitely improves therapeutic management in this high-risk population.

Changes in haemodynamics and left ventricular function during intravenous nifedipine infusion with and without additional propranolol in patients with coronary artery disease. A randomized, placebo controlled trial

The haemodynamic effects of a combined intravenous treatment of nifedipine and propranolol in ten patients with coronary artery disease compared to a single treatment with nifedipine or placebo were investigated. Nifedipine infusion resulted in a reduction of left ventricular (LV) afterload and LV volumes with an increase in heart rate and EF and no change of the double product, coronary sinus flow, LV diastolic parameters and dp/dtmax. Addition of propranolol lowers myocardial oxygen demand by reducing heart rate and dp/dtmax together with a sustained afterload reduction with no change in LV volumes and EF. The vasodilatatory action of nifedipine pretreatment balanced the negative effects of acute beta-receptor blockade on LV function and allows the reduction of myocardial oxygen demand without a deterioration of LV function.

Repeated short periods of regional myocardial ischemia: effect on local function and high energy phosphate levels

The effect of recurrent periods of ischemia on the myocardium was investigated in 15 open-chest dogs. Ischemia was produced by 3 minutes of proximal occlusion of the left anterior descending coronary artery. Each occlusion was followed by reperfusion of 3 minutes duration. Forty occlusions with a total of 120 minutes of ischemia were performed, and regional function (sonomicrometry) as well as high energy phosphates (needle biopsies) were determined at the end of the 5th, 20th, and 40th period of ischemia and reperfusion. The first periods of ischemia had a cumulative effect both on regional postischemic function (44% and 59% respectively of preischemic control after 20 occlusions) and on the ATP content, but with increasing number of occlusions the additive effects became smaller (ATP reduction/mumol/g w w/per occlusion). The ATP breakdown per occlusion was diminished with increasing number of periods of ischemia, and no significant adenosine was measured in the ischemic myocardium. Higher than normal postischemic creatine phosphate levels (9.1 mumol/g w w at the 40th reperfusion vs. 6.7 mumol/g w w control) indicated a functioning oxidative phosphorylation in the presence of an ATP utilization problem at the sarcomere level, because indicators of the cellular energy level (energy charge, free energy change of ATP hydrolysis) quickly normalized during reperfusion. Stunned myocardium is therefore not a problem of energy supply but rather of energy utilization. Reduced ATP utilization and regional dysfunction are the expressions of the same cellular defect which resides either in the ATP-splitting contractile apparatus or in the electromechanical coupling. Contractile dysfunction during reperfusion protects the heart against subsequent periods of ischemia because ATP turnover is reduced.

[Changes in diastolic ventricular properties by intravenous nifedipine infusion in patients with unstable angina pectoris]

In 16 patients with unstable angina pectoris 2 mg of nifedipine were infused intravenously for 1 hour. From coronary angiograms and cineventriculograms before and after nifedipine infusion vessel and stenosis diameters and global and regional left ventricular function were determined. Pressures in the left ventricle (Millar catheter tip manometer), aorta and pulmonary artery were measured continuously. Intravenous nifedipine infusion decreased left ventricular systolic pressure from 131.9 +/- 15.3 to 119.1 +/- 18.6 mm Hg (p less than 0.001) and mean aortic pressure from 94.4 +/- 13.6 to 85.8 +/- 15.0 mm Hg (p less than 0.01) and increased heart rate from 70.6 +/- 10.6 to 77.5 +/- 10.4, with no change in pressure rate product. Left ventricular volumes declined significantly (EDVI from 94.4 +/- 16.7 to 79.4 +/- 17.1 ml/m2 p less than 0.001, ESVI from 34.2 +/- 9.3 to 27.2 +/- 10.4 ml/m2 p less than 0.001). Ejection fraction increased slightly from 63.2 +/- 7.8 to 66.2 +/- 9.4% (p less than 0.05). Regional wall motion did not change, either in ischemic or in normally perfused areas. A change in coronary vessel or stenosis diameter was not observed. There was a remarkable 46% decrease in left ventricular enddiastolic pressure (from 11.1 +/- 5.1 to 6.0 +/- 2.3 mmHg, p less than 0.001) which developed slowly and not parallel in time to the afterload reduction. The cause appears to be the normalization of an increased left ventricular compliance documented by a significant decrease of the late diastolic dp/dV from 0.35 +/- 0.22 to 0.07 +/- 0.02 mm Hg (p less than 0.001) after nifedipine infusion. This implicates a direct myocardial effect of calcium antagonists on the ischemic myocardium.

Effect of adenosine and AICAR on ATP content and regional contractile function in reperfused canine myocardium

We investigated whether the postischemic acceleration of adenosine triphosphate (ATP) synthesis by means of precursor infusion is beneficial for the contractile function of reperfused myocardium. A coronary artery was occluded for 45 min in 21 dogs to produce a marked but reversible ischemia. During the following 3 hours of reperfusion either adenosine (n = 6) or AICAR (5-amino-imidazole-4-carboxamide-riboside) (n = 6) was infused intracoronarily by a small transfemoral catheter positioned in the LAD. ATP repletion by adenosine was nearly 50% of the deficit caused by the previous ischemia, the effect of AICAR on steady-state tissue ATP concentration was insignificant. Regional systolic function of these both groups was compared to that of a control group (n = 9) receiving only a saline infusion. We measured the regional function by subendocardially implanted ultrasound transducers using the transit time method. All three groups showed a reduction to about 25% of the initial segment shortening at the end of ischemia, followed by a quick recovery to half of the preocclusion segment shortening after reopening of the vessel. No further changes were observed in the control series during the 3 hours of reperfusion (50 +/- 10% SE segment shortening at the end). With adenosine infusion - in spite of the resulting considerable ATP elevation - no significant change of segmental contractile function occurred (44 +/- 5% SE segment shortening). Only the AICAR treated group differed from control. It produced a continuous deterioration during reflow resulting in a holosystolic bulging of -20% +/- 10% SE at the end of 3 hours of reperfusion. Our results show that there is no correlation between different ATP tissue levels achieved by adenosine infusion and systolic function in reperfused myocardium after regional reversible ischemia. We hypothesize that reperfusion dyskinesia is caused by a failure of energy utilisation rather than of energy supply.

Influence of ribose, adenosine, and "AICAR" on the rate of myocardial adenosine triphosphate synthesis during reperfusion after coronary artery occlusion in the dog

Recovery of adenosine triphosphate after myocardial ischemia is limited by the slow adenine nucleotide de novo synthesis and the availability of precursors of the nucleotide salvage pathways. We determined the adenine nucleotide de novo synthesis in the dog by infusion of [14C]glycine and the acceleration of adenine nucleotide built up by intracoronary infusion of ribose together with [14C]glycine or radiolabeled 5-amino-4-imidazolcarboxamide riboside or adenosine in the same animal model and with the same dosage of substrates (9 mmol) in postischemic and nonischemic myocardial tissue. After 45 minutes of occlusion of a side branch of the left coronary artery, the ischemic area was reperfused for 3 hours, and needle biopsies were taken for biochemical analysis. Adenine nucleotide de novo synthesis was found to be very slow (1.5 nmol/g wet weight per hour). The rate was doubled after ischemia. Adenine nucleotide synthesis was accelerated 5-fold by ribose, the basic substrate of the adenine nucleotide de novo synthesis, 9-fold by 5-amino-4-imidazolcarboxamide riboside, an intermediate of the adenine nucleotide de novo synthesis and 90-fold by adenosine, a substrate of the nucleotide salvage pathway. Therefore, only adenosine infusion resulted in a measurable increase of adenosine triphosphate levels after 3 hours of reperfusion, but over a longer time period, ribose or 5-amino-4-imidazol-carboxamide riboside also can be expected to replenish reduced myocardial adenosine triphosphate faster than adenine nucleotide de novo synthesis. Studies with radiolabeled 5-amino-4-imidazol-carboxamide riboside showed significant incorporation of radioactivity into 5-amino-4-imidazol-carboxamide ribose triphosphate which had also risen measurably during 5-amino-4-imidazol-carboxamide ribose infusion, and which is not normally found in heart muscle.