Ventricular tachycardia with narrow QRS complexes (left posterior fascicular tachycardia)

Mapping of Purkinje-related ventricular arrhythmias by a multispline catheter with small and close-paired electrodes: Comparison with conventional catheters

BACKGROUND

Precise mapping of the Purkinje fiber network is essential in catheter ablation of Purkinje-related ventricular arrhythmias (PrVAs). We sought to evaluate the mapping ability of a multi-spline duodecapolar catheter (PentaRay) for PrVAs.

METHODS

Mappings of Purkinje fibers by PentaRay catheters were compared with those by conventional mapping catheters in consecutive patients undergoing catheter ablation of PrVAs from 2015 to 2022.

RESULTS

Sixteen PrVAs (7 premature ventricular contractions or non-reentrant fascicular tachycardias [PVCs/NRFTs] and 9 fascicular ventricular tachycardias [FVTs]) were retrospectively studied. In PVCs/NRFTs, earliest preceding Purkinje potentials (PPs) could be recorded by the PentaRay catheters but not by the mapping and ablation catheters in 5 cases. At the earliest PP sites, the precedence from the QRS onset was greater, and the amplitude of the preceding potentials was higher in the PentaRay catheter compared with those in the mapping and ablation catheter (-62.0 ± 42.8 vs. -29.4 ± 34.2 ms, P = 0.02; 0.45 ± 0.43 vs. 0.09 ± 0.08 mV, P = 0.02). In FVTs, late diastolic potentials (P1) were recorded by the PentaRay catheters but not by the mapping and ablation catheters or the linear duodecapolar catheter in 2 cases. The amplitude of P1 was higher in the PentaRay catheter compared with that in the linear duodecapolar catheter and the mapping and ablation catheters (0.72 ± 0.49 vs. 0.17 ± 0.18 vs. 0.27 ± 0.21 mV, P = 0.0006, P = 0.002). The localized critical PPs, defined as the earliest preceding potentials in PVCs/NRFTs and P1 in FVTs, could be recorded in all the patients by the PentaRay catheter. The mapping ability of critical PPs of PrVAs was better with the PentaRay catheter than with the conventional mapping catheters (16/16 vs. 9/16, P = 0.004 by McNemar exact test).

CONCLUSIONS

The PentaRay catheter has clinical advantages in mapping of the Purkinje fiber network to reveal critical PPs as ablation targets of PrVAs.

Fascicular Ventricular Tachycardias: Potential Role of the Septal Fascicle

Ventricular tachycardias involving the fascicular system are amongst the most challenging and intriguing arrhythmias for cardiac electrophysiologists. Although some of the more common forms have been recognized clinically for decades, other variants continue to be characterized. Moreover, considerable uncertainty persists to date with regards to the mechanisms underpinning these arrhythmias. In this state-of-the-art review, we discuss the seminal historical and contemporary observations that have collectively advanced our understanding of fascicular ventricular tachycardias. From this base, we canvas the basic and clinical evidence supporting a potential role for the septal fascicular network and propose a new schema hypothesizing involvement of this fascicle. Although we focus primarily on the most common left posterior fascicular ventricular tachycardia, our discussion and proposal have mechanistic and therapeutic implications for the spectrum of fascicular arrhythmias.

Coronary artery bypass grafting versus stent implantation in patients with chronic coronary syndrome and left main disease: insights from a register throughout Germany

BACKGROUND

Recent randomized controlled trials have sparked debate about the optimal treatment of patients suffering from left main coronary artery disease. The present study analyzes outcomes of left main stenting versus coronary bypass grafting (CABG) in a nationwide registry in patients with chronic coronary syndrome (CCS).

METHODS

All cases suffering from CCS and left main coronary artery disease treated either with CABG or stent, were identified within the database of the German bureau of statistics. Logistic or linear regression models were used with 20 baseline patient characteristics as potential confounders to compare both regimens.

RESULTS

In 2018, 1318 cases with left main stenosis were treated with CABG and 8,920 with stent. Patients assigned for stenting were older (72.58 ± 9.87 vs. 68.63 ± 9.40, p < 0.001) and at higher operative risk, as assessed by logistic EuroSCORE (8.77 ± 8.45 vs. 4.85 ± 4.65, p < 0.001). After risk adjustment, no marked differences in outcomes were found for in-hospital mortality and stroke (risk adjusted odds ratio (aOR) for stent instead of CABG: aOR mortality: 1.08 [95% CI 0.66; 1.78], p = 0.748; aOR stroke: 0.59 [0.27; 1.32], p = 0.199). Stent implantation was associated with a reduced risk of relevant bleeding (aOR 0.38 [0.24; 0.61], p < 0.001), reduced prolonged ventilation time (aOR 0.54 [0.37 0.79], p = 0.002), and postoperative delirium (aOR 0.16 [0.11; 0.22], p < 0.001). Furthermore, stent implantation was associated with shorter hospital stay (- 6.78 days [- 5.86; - 7.71], p < 0.001) and lower costs (- €10,035 [- €11,500; - €8570], p < 0.001).

CONCLUSION

Left main stenting is a safe and effective treatment option for CCS-patients suffering from left main coronary artery disease at reasonable economic cost. Coronary artery bypass grafting versus stent implantation in patients with chronic coronary syndrome and left main disease: insights from a register throughout Germany. All cases with chronic coronary syndrome and left main stenosis treated in 2018 in Germany either with left main stenting or coronary bypass grafting were extracted from a nation-wide database. In-hospital outcomes were compared after logistic regression analysis.

Mapping and Ablation of Fascicular Tachycardias (Reentrant and Nonreentrant)

Fascicular ventricular tachycardia (FVT) usually involves the left fascicular system; namely the left posterior fascicle, anterior fascicle, and rarely the upper septal fascicle. It may also involve the right Purkinje arborization. This tachycardia can be seen in normal heart or in the setting of structural heart diseases. Monomorphic FVT can be reentrant or nonreentrant and verapamil-sensitive left FVT is the second most common type of idiopathic ventricular tachycardia (VT) after right ventricular outflow tract VT. This article focuses on the practical approach for both reentrant and nonreentrant FVT, explaining the mechanism, electrocardiographic features, and electrophysiologic features of FVT.

Idiopathic Left Ventricular Tachycardia Originating in the Left Posterior Fascicle

Ventricular tachycardias originating from the Purkinje system are the most common type of idiopathic left ventricular tachycardia. The majority if not all of the reentrant circuit involved in this type of tachycardia is formed by the Purkinje fibres of the left bundle branch, particularly the left posterior fascicle. In general, slowly conducting Purkinje fibres (P1) form the antegrade limb, and normally conducting Purkinje fibres (P2) form the retrograde limb of the reentrant circuit of the ventricular tachycardia originating from the left posterior fascicle. Elimination of the critical Purkinje elements in the reentrant circuit is the route to successful ablation. While the reentrant circuit identified by activation mapping provides the roadmap to ablation targets, comparing the difference in the His-ventricular interval during sinus rhythm and tachycardia also helps to identify the critical site in the reentrant circuit.

Left main coronary artery disease: pathophysiology, diagnosis, and treatment

The advent of coronary angiography in the 1960s allowed for the risk stratification of patients with stable angina. Patients with unprotected left main coronary artery disease have an increased risk of death related to the large amount of myocardium supplied by this vessel. Although coronary angiography remains the preferred imaging modality for the evaluation of left main coronary artery stenosis, this technique has important limitations. Angiograms of the left main coronary artery segment can be difficult to interpret, and almost one-third of patients can be misclassified when fractional flow reserve is used as the reference. In patients with clinically significant unprotected left main coronary artery disease, surgical revascularization was shown to improve survival compared with medical therapy and has been regarded as the treatment of choice for unprotected left main coronary artery disease. Two large-scale clinical trials published in 2016 support the usefulness of catheter-based revascularization in selected patients with unprotected left main coronary artery disease. In this Review, we describe the pathophysiology of unprotected left main coronary artery disease, discuss diagnostic approaches in light of new noninvasive and invasive imaging techniques, and detail risk stratification models to aid the Heart Team in the decision-making process for determining the best revascularization strategy for these patients.

Spectrum of Fascicular Arrhythmias

Fascicular arrhythmias encompass a wide spectrum of ventricular arrhythmias that depend on the specialized conduction system of the right and left ventricles. These arrhythmias include premature ventricular complexes, monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and ventricular fibrillation. These arrhythmias may be organized by mechanism, including intrafascicular reentry, interfascicular reentry, and focal. Mapping and ablation of the fascicular system can result in high cure rates of debilitating and potentially life-threatening arrhythmias. When approaching these arrhythmias, careful consideration of the structure of the His Purkinje system as well as their electrophysiologic properties may help guide even the most complex of arrhythmias.

[Ablation of idiopathic fascicular ventricular tachycardia]

Idiopathic fascicular ventricular tachycardia is an important and not very rare cardiac arrhythmia with specific electrocardiographic features and therapeutic options. Ventricular tachycardia is characterized by relatively narrow QRS complex and right bundle branch block pattern. The QRS axis depends on which fascicle is involved in the re-entry. Left axis deviation is noted with left posterior fascicular tachycardia and right axis deviation with left anterior fascicular tachycardia. A left septal fascicular tachycardia with normal QRS axis is also possible. Idiopathic fascicular tachycardia is usually seen in individuals without structural heart disease. Response to verapamil is an important feature of fascicular tachycardia. In some cases intravenous adenosine may also terminate the arrhythmia. During electrophysiology study, presystolic or diastolic potentials precede the QRS, presumed to originate from the Purkinje fibers. The potentials can be recorded during sinus rhythm and ventricular tachycardia in many patients with fascicular tachycardia. This potential (so-called Purkinje potential) has been used as a guide to catheter ablation. Correct diagnosis of fascicular tachycardia is very important because catheter ablation is very effective in the treatment of this type of ventricular tachycardia. In this review, we describe three patients with idiopathic ventricular tachycardia and their successful catheter ablation, and summarize the actual knowledge of the diagnosis and management of this special ventricular tachycardia.

Percutaneous coronary intervention for left main coronary artery disease

Coronary artery bypass surgery is the currently accepted treatment for unprotected left main coronary artery disease. Currently, the data supporting the safety and efficacy of stents for unprotected left main coronary disease are derived mostly from nonrandomized, single-center studies or registries. These results appear promising but large randomized trials are needed to guide therapy of this potentially lethal disease.

A case of a borderline-broad complex tachycardia

Prompt and correct treatment of broad complex tachycardias in the emergency department can often be life-saving to the patient and satisfying for the emergency physician. They, however, are often a diagnostic challenge. Here, we present a case of posterior fascicular ventricular tachycardia, an idiopathic form of ventricular tachycardia that occurs in patients without coronary artery disease and verapamil sensitive. The differential diagnoses of posterior fascicular ventricular tachycardia and supraventricular tachycardia with aberrancy will also be discussed.

Comparison of X-ray fluoroscopy and interventional magnetic resonance imaging for the assessment of coronary artery stenoses in swine

The accuracy of a two-step interventional MRI protocol to quantify coronary artery disease was compared to the clinical gold standard, X-ray angiography. Studies were conducted in nine swine with a surgically induced stenosis in the proximal left circumflex coronary artery. The two-step protocol consisted of catheter-directed magnetic resonance angiography (MRA), which was first used to localize the stenosis, followed by MRI cross-sectional images to quantify the degree of stenosis without the use of contrast agent. Line signal intensity profiles were drawn across the vessel diameter at the stenosis site and proximal to the stenosis for each data set to measure percentage stenosis for each animal. Catheter-directed MRA successfully detected eight of nine stenoses. Cross-sectional MRI accurately quantified each stenosis, with strong agreement to the measurements made using X-ray fluoroscopy (intraclass correlation coefficient = 0.955; P < 0.05). This study demonstrates that in the future interventional MRI may be an alternative to X-ray angiography for the detection and quantification of coronary artery disease.

Fascicular ventricular tachycardia: an uncommon but distinctive form of ventricular tachycardia

Emergency physicians often encounter wide-QRS-complex tachyarrhythmias, which pose both a diagnostic and therapeutic challenge. Most such rhythms are the result of ventricular tachycardia (VT) related to coronary artery disease. However, the spectrum of VT is broad, with several distinct clinical entities, some of which are benign in their clinical course. Idiopathic fascicular VT is one such entity. We present two cases of idiopathic fascicular VT and discuss the unique electrocardiographic, electrophysiologic, and electropharmacologic properties that make it an identifiable and treatable arrhythmia in the ED.

Radiofrequency catheter ablation of idiopathic ventricular tachycardias in children

We performed radiofrequency catheter ablation of idiopathic ventricular tachycardia in six children. In four, the ventricular tachycardia originated in the left ventricle, in two it originated in the right ventricular outflow tract. In 5/6 (83%) the RF procedure was successful; there were no complications.

Left main intervention revisited: early and late outcome of PTCA and stenting

We reviewed our experience with 28 unselected, consecutive patients undergoing left main coronary artery (LMCA) angioplasty who had been considered unsuitable for coronary artery bypass graft surgery (CABG). Fourteen patients (50%) had a protected LMCA circulation. Balloon angioplasty was performed in 11 patients (39.3%), and stents were implanted in 17 patients (60.7%). The procedure was elective in 22 patients (78.6%) and acute in the setting of myocardial infarction/cardiogenic shock in 6 (21.4%). The mean follow-up duration was 15.9 +/- 12 months. There were 5 early (before hospital discharge) and 4 late deaths (total 32.1%), 1 myocardial infarction (3.6%), 6 repeat angioplasties (21.4%), and 3 subsequent CABG (10.7%). All 5 early deaths occurred in patients with cardiogenic shock and unprotected circulation. The results of our study suggest that when patients have prohibitive surgical risks, elective LMCA angioplasty and/or stenting may be undertaken with a high procedural success rate. However, our data do not support intervention in the presence of acute myocardial infarction/cardiogenic shock.

Radiofrequency catheter ablation of idiopathic ventricular tachycardia originating in the anterior fascicle of the left bundle branch

INTRODUCTION

Idiopathic ventricular tachycardia (VT) originating in or close to the anterior fascicle of the left bundle is rare. A patient with no structural heart disease and VT with a right bundle branch block configuration and right-axis deviation underwent an electrophysiologic examination.

METHODS AND RESULTS

Both endocardial activation mapping during VT and pacemapping were performed via a transseptal approach to localize the site of origin of the VT. Endocardial recordings of the His bundle and the posterior and anterior fascicles of the left bundle branch revealed an origin of the VT in or close to the anterior fascicle. The Purkinje potential at that site preceded the QRS complex by 20 msec, with pacemapping showing an optimal match between the paced rhythm and the clinical VT. RF energy delivered at this site terminated the VT. A left anterior hemiblock appeared after RF ablation. Ten months later, the patient is free from recurrences of VT.

CONCLUSIONS

Idiopathic VT originating in or close to the anterior fascicle was cured by RF ablation. A Purkinje potential preceding the QRS during tachycardia and an optimal pacemap were used to guide RF ablation.

Ventricular tachycardia with narrow QRS duration, a right bundle branch block pattern, and right axis deviation abolished by catheter manipulation

A 25-year-old women underwent electrophysiologic evaluation for sustained normal QRS complex tachycardia with a pattern of right bundle branch block and right axis deviation. Ventricular tachycardia was diagnosed by demonstrating fusion beats, atrioventricular dissociation, and bundle of His potential activation, which began before the onset of each QRS complex. A single ventricular extrastimulus was capable of easily provoking the tachycardia. There was an inverse relationship between the coupling interval of the first extrastimulus and the interval of the first tachycardia beat, suggesting reentry as the mechanism. The tachycardia was unexpectedly abolished during catheter manipulation in the left ventricle and has never recurred during 1 year of follow-up evaluation. The tachycardia was thought to be an unusual form of interfascicular tachycardia or microreentrant fascicular tachycardia.

Diagnostic clues from the surface ECG to identify idiopathic (fascicular) ventricular tachycardia: correlation with electrophysiologic findings

INTRODUCTION

An RS interval > 100 msec in precordial leads has been recently described for the diagnosis of ventricular tachycardia (VT). The aim of this study was to assess the value of this criterion when applied to patients with right bundle branch block pattern, left-axis deviation (fascicular) VT sensitive to verapamil.

METHODS AND RESULTS

Eleven patients (mean age 31 +/- 11 years; range 16 to 51) had a mean heart rate of 164 +/- 37 beats/min (range 107 to 230) during VT. The QRS complex axis was -92 degrees +/- -15 degrees (range -80 to -115). The mean QRS duration was 121 +/- 9 msec (range 105 to 140). The mean RS interval was 67 +/- 9 msec (range 60 to 80). Fusion beats were present in 2 patients (18%), and AV dissociation confirmed by electrophysiologic study was found on ECG in 8 (73%) of 11. During tachycardia, the QRS-H' interval was 19 +/- 10 msec (range 10 to 30) in 6 of 11 patients. In seven patients, a fast, unique (or double) presystolic potential lasting 32 msec (range 12 to 40) occurring before the onset of the QRS complex was found at the site of origin of VT, localized in the inferior apical left ventricular septum. In all cases, VT was successfully treated by catheter ablation.

CONCLUSION

A wide QRS complex tachycardia with right bundle branch block and left-axis deviation sensitive to verapamil observed in a young patient without structural heart disease should not be confused with supraventricular tachycardia with aberrancy but rather suggests the presence of fascicular VT. As opposed to VT associated with structural heart disease, the RS interval is < 80 msec in all precordial leads in all cases. Independent of this parameter, AV dissociation detectable on surface ECG has a sensitivity of 73%, which increases to 82% in the presence of fusion beats.

Strategies for the palliation of severe unprotected left main coronary artery disease: use of newer technologies

Angioplasty of unprotected left main coronary artery lesions is associated with high procedural and late mortalities. We describe the successful use of rotational coronary atherectomy with prophylactic supportive measures in the management of a heavily calcified unprotected left main lesion. This report demonstrates that high-risk lesions, previously regarded as unapproachable, may be safety treated with newer technologies.

Clinical and electrophysiologic spectrum of fascicular tachycardias

The purpose of this report is to describe the clinical and electrophysiologic findings for patients with fascicular tachycardia (FT). Eight patients with FT, defined as tachycardia with HV interval during tachycardia less than that of HV of conducted impulses, were studied. ECG findings during FT included right bundle block and superior axis (four patients), right bundle branch block and inferior axis (one patient), and nonspecific intraventricular conduction delay (three patients). In three patients, entrainment as well as the ability to initiate and terminate the tachycardia favored a reentrant mechanism. In others, tachycardia initiation only over a critical range of paced cycle lengths and the incessant nature of the tachycardia or the presence of other atrial or ventricular foci favored a mechanism of either abnormal automaticity or triggered rhythms. Catheter ablation was successful in two of five patients in whom it was attempted. In conclusion, the ECG expression of FT is variable, depending on the site of origin of the arrhythmia in the ventricular specialized conduction system. Similarly, a variety of mechanisms and different foci may be associated with FT. Selected individuals may respond to catheter ablative therapy.

Coronary angiography with 5 French diagnostic catheters may miss an ostial left main stenosis

Critical ostial left main disease may lead rapidly to sudden death and is, therefore, of paramount importance to diagnose. While the number of cardiac catheterizations is increasing, government and third party reimbursement sources are imposing pressure to perform more studies in an outpatient setting, as the economic resources for medical procedures are shrinking. Outpatient cardiac catheterization requires the patient to ambulate within several hours after the procedure. In order to allow patients to safely ambulate early after their procedures, 5 French catheters are often used (whether the femoral or brachial approach is used) rather than the standard 7 French catheters. We describe a patient with an ostial left main stenosis that was not visualized when coronary arteriography was performed using a diagnostic 5 French catheter. Selective intubation of the left main coronary artery was easily achieved without damping of the pressure tracing. Selective coronary angiography did not demonstrate the ostial stenosis, and there appeared to be a normal amount of contrast refluxing into the aortic root. When the patient returned for an angioplasty and a guiding angiogram was performed with an 8 French catheter, an ostial stenosis was evident with coronary angiography.

Nondiagnosed left main ostial stenosis partly due to the use of 5 French coronary angiographic catheters

Two cases have been reported in which the use of 5 F angiographic catheters is associated with a failure to diagnose an ostial stenosis of the left main coronary artery (LMCA). In both cases, the erroneous diagnosis led to an inappropriate indication for percutaneous transluminal coronary angioplasty (PTCA) on other stenosed vessels, and the ostial left main lesion was unexpectedly discovered when using 8F guiding catheters. It is supposed that the ability of performed 5F catheters to pass easily through an ostial lesion makes detection of such proximal stenosis much more difficult. We suggest that the choice of 5F catheters must be approached with caution when left main disease is potentially expected from the clinical features.

Isolated left coronary ostial stenosis--a case report

A patient with isolated left coronary ostial stenosis proved by coronary angiography is presented. Isolated left coronary ostial stenosis is a rare condition of unknown etiology. Unique clinical and angiographic profiles are discussed in detail with a review of the literature, along with a suggestion of a natural history distinct from that usually seen in atherosclerotic coronary diseases.

Narrow QRS complex tachycardia with atrioventricular dissociation

We describe the case of a 22-year-old man who had frequent episodes of narrow QRS complex tachycardia with atrioventricular dissociation. The ECG during sinus rhythm showed normal PR and QRS intervals, but it showed a left bundle branch block configuration during atrial pacing or after injection of verapamil. An electrophysiological study demonstrated that the patient had nodoventricular Mahaim fibers. The narrow QRS complex tachycardia was explained by a circuit involving antegrade conduction via the atrioventricular nodo-His axis and retrograde conduction via the nodoventricular bypass tract.

Paroxysmal fascicular tachycardia and ventricular tachycardia due to mechanical stimulation by a mitral valve prosthesis

Electrophysiologic studies were performed in a woman who had two varieties of paroxysmal wide QRS tachycardia after mitral valve replacement with a Starr-Edwards prosthesis. One tachycardia originated in the left anterior fascicle; QRS complexes were 100 ms wide and resembled right bundle branch block with left posterior fascicular block, and a His bundle potential preceded each QRS by an interval of 20 ms (compared with 50 ms during sinus rhythm). The other tachycardia originated in the left ventricle. Clinical and echocardiographic observations suggested that the tachycardias were caused by mechanical stimulation of the interventricular septum by the mitral prosthesis.

Isolated coronary ostial stenosis

We have examined 5 patients with typical angina pectoris and found them to have left coronary ostial stenosis without evidence of any other coronary arterial disease and without evidence of aortic disease (Takayasu aortitis, syphilitic aortitis, or familial hypercholesterolaemia). All five patients were female aged between 38 and 53 years, a striking difference from the normal 7:1 male:female ratio for atherosclerotic coronary artery disease. It may be that these patients represent a rare but distinct syndrome. The angiographic diagnosis can be difficult but a pressure drop as the catheter tip engages the ostium and lack of spill-over of contrast into the sinus of Valsalva are findings that should lead the angiographer to suspect ostial stenosis.

Paroxysmal fascicular tachycardia: electrophysiologic characteristics and treatment by catheter ablation

A 69 year old man with ischemic heart disease underwent electrophysiologic evaluation for paroxysmal wide QRS tachycardia, the configuration of which was identical to that recorded during sinus rhythm, that is, right bundle branch block, left anterior fascicular block and anterior myocardial infarction. Electrocardiographic recordings during tachycardia showed atrioventricular dissociation and His bundle activation occurring 5 ms after the onset of the QRS complex recorded on the surface electrocardiogram, consistent with a left posterior fascicular tachycardia. All traditional therapeutic attempts failed to prevent frequent recurrences of tachycardia, which was finally ablated by three 300 J shocks delivered through an electrode catheter positioned in the posterobasal region of the left ventricular septum.

Evaluation of the patient with wide QRS tachycardia

Acute and long-term therapy as well as prognosis in patients with wide QRS tachycardia differ depending on the mechanism of the arrhythmia. Twelve-lead electrocardiography and prolonged electrocardiographic monitoring are often diagnostic. However, additional techniques such as esophageal and right atrial electrocardiography, or His bundle electrocardiography with detailed electrophysiologic studies, are sometimes necessary to delineate the mechanism of the arrhythmia.

Mortality related to cardiac catheterization and angiography

During a 14-month period, 75 deaths occurring in relation to 53,581 cardiac catheterizations were consecutively and prospectively reported to the Registry Committee of the Society for Cardiac Angiography. Three of the patients died several days after their catheterization from an unrelated cause and are excluded from this analysis. There were 21 patients (group I) who arrived at the laboratory in extremis and whose deaths were expected irrespective of the catheterization. Most of these patients suffered from recent myocardial infarctions and cardiogenic shock, or had complex congenital malformations. In 35 patients (group II), a cardiovascular complication occurring during the catheterization resulted in death. In 16 patients (group III) catheterization seemed uneventful, but death occurred suddenly 10 min to 10 h after the procedure. Of these 16 patients, eight had left main coronary artery obstruction greater than or equal to 90%, five had three-vessel disease all with 90% obstructions, one had 2-vessel disease both with 90% obstructions, and who had critical aortic stenosis. The 51 unexpected deaths (groups II and III) were considered to be causally related to the procedure, a mortality rate of 0.10%. Subsets with an increased mortality rate (M), were patients with: a) left main disease greater than 50% (M = 0.94%); b) ejection fraction less than 30% (M = 0.54%); c) NYHA class III or IV (m = 0.24%); d) age over 60 years (M = 0.23%); or e) three-vessel disease (M = 0.13%). In conclusion, catheterization related mortality occurs mostly in patients with far advanced cardiac disease. Nearly 1/3 of the unexpected deaths occurred suddenly after a seemingly uneventful procedure. Close monitoring after catheterization of patients with similar characteristics (left main disease greater than or equal to 90%, or three-vessel disease all greater than or equal to 90%) might disclose avenues for reducing mortality occurring after catheterization.

Coronary ostial stenosis

Coronary ostial stenosis as a complication of atherosclerosis is a rarely emphasized angiographic finding. Its recognition is important because of the adverse prognosis of left main stenosis and the inherent risks during catheterization of these patients. Recently 3 patients were identified with left coronary ostial stenosis. A clinical picture emerged during coronary angiography characterized by an abrupt fall in catheter tip pressure associated with symptoms of dyspnea and chest pain. Contrast media injections into the sinus of Valsalva, in right anterior oblique and left anterior oblique projections, revealed characteristic angiographic changes.

Congenital atresia of the left main coronary artery ostium

Three patients with the rare anomaly of congenital absence of the ostium of the left main coronary artery are presented. In two of the patients, aged 50 and 52 respectively, the diagnosis was established during selective coronary cineangiography for a severe anginal syndrome. The third patient, a 16-year-old-girl, underwent cardiac catheterization for investigation of a congenital heart malformation, when a single right coronary artery was demonstrated with absence of the main coronary artery ostium. Two patients underwent successful aortocoronary bypass grafting. In view of the occurrence of sudden death and massive myocardial infarction in adult patients shown to have severe or complete obstruction of the left main coronary artery, it is suggested that adult patients with this condition, who require open-heart surgery for any other cardiac disorder, should undergo aortocoronary bypass grafting concurrently even prior to the development of anginal symptoms. Children shown to have this anomaly should be subjected to long-term follow-up and have an aortocoronary bypass graft performed when symptoms of coronary insufficiency develop.

[Clinical value of His bundle electrography (author's transl)]

Methodical problems, indication and clinical implication of His bundle electrography are discussed. In 200 successive patients undergoing His bundle electrography and atrial stimulation the indication was as follows: Intraventricular conduction defects in 24%, A-V block in 21%, sick sinus syndrome in 20%, preexcitation in 17%, and complex arrhythmias in the remaining cases. In 38% of the patients did the HBE prove to be of help by providing information not available after analysis of the surface ECG. In 22% this technique contributed essentially to the management of these patients. In spite of dificiencies of our knowledge of the basic mechanisms, specific therapy, and prognosis of various arrhythmias His bundle electrography is clinically useful in selected patients. Therefore, this method has become a routinely used clinical tool.