Unsuspected coronary artery disease as cause of chronic atrioventricular block in middle age

Attention has recently been drawn to the relatively poor prognosis of middle aged patients paced for chronic atrioventricular block when age-linked expectation of life is taken into account, and it has been suggested that this may be the result of underlying coronary artery disease, despite the absence of symptoms to suggest this. It was the purpose of this study to determine the incidence of unsuspected coronary artery disease in middle aged patients presenting with chronic atrioventricular block. Studies were made on a consecutive series of 30 patients aged 45 to 65 (mean age 56 years) with chronic atrioventricular disease who had been referred for pacing. Patients presenting with acute myocardial infarction or angina or with sinuatrial disease without atrioventricular disease were excluded. Coronary arteriography disclosed the presence of severe coronary artery disease in 13 patients. Of the remaining 17 patients, four had congestive cardiomyopathy, two had hypertrophic cardiomyopathy, one had aortic stenosis, and in 10 patients the aetiology of the heart block was unknown. Myocardial revascularisation was undertaken in six patients with paroxysmal atrioventricular block caused by coronary artery disease. Operation did not result in any sustained improvement in atrioventricular conduction.     

Unsuspected coronary artery disease as cause of chronic atrioventricular block in middle age.

Attention has recently been drawn to the relatively poor prognosis of middle aged patients paced for chronic atrioventricular block when age-linked expectation of life is taken into account, and it has been suggested that this may be the result of underlying coronary artery disease, despite the absence of symptoms to suggest this. It was the purpose of this study to determine the incidence of unsuspected coronary artery disease in middle aged patients presenting with chronic atrioventricular block. Studies were made on a consecutive series of 30 patients aged 45 to 65 (mean age 56 years) with chronic atrioventricular disease who had been referred for pacing. Patients presenting with acute myocardial infarction or angina or with sinuatrial disease without atrioventricular disease were excluded. Coronary arteriography disclosed the presence of severe coronary artery disease in 13 patients. Of the remaining 17 patients, four had congestive cardiomyopathy, two had hypertrophic cardiomyopathy, one had aortic stenosis, and in 10 patients the aetiology of the heart block was unknown. Myocardial revascularisation was undertaken in six patients with paroxysmal atrioventricular block caused by coronary artery disease. Operation did not result in any sustained improvement in atrioventricular conduction.     

Dissociation of the atrioventricular node in acute inferior wall myocardial infarction. 1. Transverse dissociation (alternate Wenckebach periods)

Two cases of alternate Wenckebach periods developing during the acute phase of inferior wall myocardial infarction are presented. In both cases, syncope occurred and severe bradyarrhythmia was recorded on the day of admission. Electrophysiologic study performed in one patient and a narrow QRS complex in the other patient during the alternate Wenckebach periods confirmed the atrioventricular node as the level of block. Transverse dissociation of the atrioventricular node with two (or more) levels of block is the most acceptable explanation for this phenomenon. We suggest that alternate Wenckebach periods occurring during the acute phase of inferior wall myocardial infarction is a severe bradyarrhythmia, and prophylactic temporary pacing is recommended.     

Phasic coronary arterial flow velocity during arrhythmias in man

The influence of cardiac arrhythmias on coronary arterial flow velocity studied by means of a Doppler catheter flowmeter system is described in 47 patients. The arrhythmias examined included atrial and ventricular extrasystoles, atrial fibrillation, pacemaker-induced atrial tachycardia, paroxysmal atrial tachycardia, ventricular tachycardia, Wenckebach second degree atrioventricular block and complete heart block.     

Latent defects of atrioventricular conduction in right coronary artery disease

The purpose of this study was to investigate the occurrence of latent defects in AV conduction in patients with right coronary artery disease. Twenty-two patients with greater than 50 per cent obstruction of the right coronary artery and a predominant right coronary artery system or pattern were studied with His bundle electrograms and determinations were made of the functional refractory period of the AV node and the point at which AV Wenckebach developed during rapid atrial pacing with a fixed cycle length. The patients were studied prior to or at least six months after the onset of clinical or electrocardiographic evidence of acute infarction. Similar measurements were made in eighteen control subjects with less than 50 per cent occlusion of the right coronary artery. The results showed significant prolongation of the functional refractory period (467 ± 63 msec. for patients with right coronary disease versus 408 ± 43 msec. in the control group; P <0.01) and earlier development of atrioventricular Wenckebach during rapid atrial pacing (143 ± 22 BPM in the coronary obstruction group versus 172 ± 19 BPM in the control group; P<0.01) in patients with significant disease of the right coronary artery when compared to the control group. Although all patients were found to have resting intervals on the His bundle electrogram within normal limits, the group with right coronary obstruction had slightly longer values for the resting P-H interval (122 ± 19 msec. versus 101 ± 31 msec. in the control group; P<0.05). This study establishes that latent defects in atrioventricular conduction exist in patients with significant disease of the right coronary artery in the absence of acute infarction.     

Myocardial bridging of the left anterior descending coronary artery and right coronary artery in a patient with mitral valve stenosis

Myocardial bridging is defined as the intramural course of a major epicardial coronary artery, and is mostly confined to the left ventricle and the left anterior descending coronary artery (LAD). Although it is considered to be a benign anomaly, it can lead to such complications as acute myocardial infarction, ventricular tachycardia, syncope, atrioventricular block and sudden cardiac death. Isolated myocardial bridging of the right coronary artery (RCA) and left circumflex artery have been reported in the literature In our case, myocardial bridging was observed in both the LAD and the RCA in a patient with mitral valve stenosis.     

碎裂QRS波与急性冠状动脉综合征患者冠状动脉病变及预后的关系

目的:研究心电图导联上碎裂QRS波(fQRS)在急性冠状动脉(冠脉)综合征(ACS)患者的发生情况,以及与冠脉病变和预后的关系。方法:连续入选ACS患者,根据是否存在fQRS进行分组,分析fQRS与冠脉病变范围、狭窄程度及侧支循环、心脏骤停、严重心律失常及左室射血分数(LVEF)的关系。结果:急性心肌梗死患者fQRS发生率明显高于不稳定心绞痛,ACS患者中fQRS组3支病变、完全闭塞病变、侧支循环、心脏骤停、室性心动过速和(或)心室颤动的发生率较无fQRS组明显升高,LVEF低于无fQRS组。2组在缓慢型心律失常[Ⅱ度二型房室传导阻滞和(或)Ⅲ度房室传导阻滞]无显著性差异。结论:ACS患者fQRS主要发生在急性心肌梗死,fQRS的出现可作为预测ACS冠脉病变程度及预后的指标。     

Electrocardiographic manifestations and clinical significance of atrioventricular nodal alternating Wenckbach periods

Atrioventricular nodal alternating Wenckebach periods were defined as episodes of 2:1 atrioventricular block in which there was a gradual increase in transmission intervals of conducted beats ending in two or three consecutively blocked atrial impulses. This is one of the mechanisms whereby 2:1 atrioventricular block progresses into 3:1 or 4:1 atrioventricular block. Alternating Wenckebach periods appear during rapid atrial pac,ng (even in the absence of depressed atrioventricular nodal function), provided that the atria can be captured at a rate fast enough to allow for the occurrence of this phenomenon. Treatment of atrial flutter with digoxin and quinidine produces alternating Wenckebach's periods, with associated electrocardiographic changes specific for the type of drug given. In patients with "atrial tachycardia with atrioventricular block" due to digitalis intoxication or with primary disease of the conducting system or with acute myocardial infarction, there are coexisting severe arrhythmias and clinical symptoms requiring almost immediate pharmacologic or electrical therapy. We conclude that atrioventricular nodal alternating Wenckebach's periods are common and frequentyly transient and that they occur in a variety of clinical conditions, most of which are benign; however, contrary to what is commonly accepted, some episodes appear in clinical settings requiring prompt pharmacologic or electrical treatment.     

急性下壁心肌梗塞伴房室传导阻滞发生与冠状动脉病变的关系

目的 :研究急性下壁心肌梗塞伴房室传导阻滞 (AVB)发生与冠状动脉病变之间的关系。　　方法 :40例急性下壁心肌梗塞患者分为房室传导阻滞组 (AVB组 ,n=16 )和无房室传导阻滞组 (NAVB组 ,n=2 4) ,分析两组间肌酸激酶峰值、冠状动脉病变支数、多支冠状动脉严重病变及优势型冠状动脉狭窄程度对 AVB发生的影响。　　结果 :AVB发生与优势型冠状动脉狭窄严重程度有关 ,狭窄程度越高 ,则 AVB发生率越高 ,L ogistic多元回归分析显示优势型冠状动脉狭窄程度是唯一有意义的危险因素 (P=0 .0 0 2 9,OR=8.86 0 1)。　　结论 :优势型冠状动脉的严重阻塞是 AVB发生的一个独立因素。     

心电图J／R比值对下壁心肌梗死并发房室阻滞的预测价值

目的探讨急性下壁心肌梗死早期心电图表现对高度房室阻滞的预测价值以及与冠状动脉病变的关系。方法分析97例急性下壁心肌梗死患者早期心电图（下壁导联）J／R≥0．5的发生情况，部分病例结合冠脉造影结果，探讨其对房室阻滞的预测价值。结果27例（21．6％）在心肌梗死急性期发生二度以上房室阻滞。有房室阻滞者，心电图下壁导联J／R≥0．5多于无房室阻滞者（69．56％vs30．44％，p〈0．01）。冠状动脉造影显示，有房室阻滞者，右冠状动脉近中段的高度狭窄明显多于无房室阻滞者（100％vs58．33％）。结论急性下壁心肌梗死伴房室阻滞者的病损冠脉以右冠状动脉多见，下壁导联心电图J／R≥0．5对下壁心肌梗死合并房室阻滞的发生有一定的预测价值。     

Three cases of single coronary artery

Single coronary artery has been considered a minor coronary anomaly without clinical importance. With the wide spread of coronary angiography, however, the disease has been reported to develop complications at a high rate, such as angina, myocardial infarction and arrhythmia. We report three patients with single coronary artery with several complications. Case 1: A 56-year-old woman having a past history of diabetes mellitus and myocardial infarction was admitted because of the recently developed frequent attacks of effort angina. Treadmill test was positive and thallium-201 exercise myocardial scintigraphy revealed redistribution in the lateral wall. Ascending aortogram suggested that the right coronary artery (RCA) arose from the left sinus of Valsalva. An injection into the right sinus of Valsalva revealed no coronary ostium. Selective left coronary angiogram resulted in the diagnosis of single coronary artery (Smith's type 2) with 90% stenosis in the left circumflex artery (LCX). Left ventriculogram showed hypokinesis in the anterolateral wall. PTCA performed on this patient revealed clinical and nucleomedical improvement. Case 2: A 48-year-old man experienced chest pain and syncope. Electrocardiogram revealed ST-elevations in II, I and a VF, sinus bradycardia and atrioventricular junctional rhythm. Angiography resulted in the diagnosis of single coronary artery (Smith's type 2) with 75% stenosis in the RCA. Ergonovine test was positive. Case 3: A 69-year-old man complained of chest pain. Electrocardiogram showed complete right bundle branch block, sinus bradycardia and atrioventricular junctional rhythm. Cardiac catheterization revealed that this was also a case of single coronary artery (Smith's type 2) with no significant stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Conduction disturbances and paroxysmal atrial fibrillation during acute inferior myocardial infarction

Associated symptoms and conduction disturbances are reported during acute inferior myocardial infarction. Differentiation of right coronary artery from left circumflex artery occlusion may be difficult since both can present an electrocardiographic pattern of inferior myocardial infarction. Paroxysmal atrial fibrillation is considered a frequent complication of acute myocardial infarction and the patients with paroxysmal atrial fibrillation probably should be targeted for earlier and more aggressive treatment. These patients in the thrombolytic era have a better overall outcome than counterparts in the prethrombolytic era. We describe a case of conduction disturbances and paroxysmal atrial fibrillation in a 51-year-old Italian man with acute inferior myocardial infarction and right coronary artery stenosis.     

Coronary angiographic significance of left anterior fascicular block during acute myocardial infarction

The clinical and angiographic significance of isolated left anterior fascicular block occurring during the early stage of acute myocardial infarction was studied in 141 consecutive patients who underwent cardiac catheterization before hospital discharge. Left anterior fascicular block occurred in 15 of the 62 patients with an anterior wall infarction and in 13 of the 79 with an inferior infarction. None of the clinical characteristics differed among patients with or without left anterior fascicular block. The number of coronary vessels with significant stenosis, the Friesinger and the Gensini scores for severity of stenosis and the ejection fraction were also similar in the two groups. Patients with left anterior fascicular block had more severe narrowing of the coronary artery supplying the infarct zone (88 +/- 21 versus 70 +/- 35%, p less than 0.001) and tended to have less developed collateral circulation (collateral score 0.7 +/- 0.8 versus 1 +/- 0.8, p = 0.10). A significant stenosis of the left anterior descending coronary artery was found as frequently in patients with as in those without left anterior fascicular block (64 versus 65%); 29% of the patients with inferior wall infarction and left anterior fascicular block had left anterior descending coronary artery stenosis compared with 47% of the patients without this conduction disturbance (no significant difference). When the infarction was located anteriorly, a significant stenosis of the proximal segment of the left anterior descending coronary artery was present in 47% of the patients with and in 45% of the patients without left anterior fascicular block.(ABSTRACT TRUNCATED AT 250 WORDS)     

Paroxysmal Atrioventricular Block in a Relatively Young Patient with COVID-19

Cardiac involvement has been reported in patients with coronavirus disease 2019 (COVID-19). We herein report a 41-year-old man who presented with recurrent paroxysmal atrioventricular block without showing significant cardiac injuries or comorbidities. The patient was diagnosed with COVID-19 and admitted to our hospital, where he was noted to have paroxysmal atrioventricular block. Cardiac biomarkers, echocardiography, and cardiac magnetic resonance imaging findings were fairly normal. An endomyocardial biopsy performed before the implantation of a permanent pacemaker revealed mild myocardial fibrosis without inflammatory infiltrates. The unusual myocardial involvement of the novel coronavirus was suspected.     

Alternating Wenckebach periods occurring in the atria, His-Purkinje system, ventricles and kent bundle

Alternating Wenckebach periods were defined as episodes of 2:1 block during which there was a gradual prolongation of the transmission intervals preceding the appearance of 3:1 or 4:1 block. Alternating Wenckebach periods occurring within the His-Purkinje system in symptomatic patients with right bundle branch block could have resulted from involvement of the His bundle only, the left bundle branch only or both structures simultaneously. Alternating Wenckebach patterns presumably occurring in the reentry pathway of ventricular extrasystoles and in the tissues surrounding an ectopic atrial focus or bipolar pacing electrodes were manifested in the coupling intervals of the premature beats; in the P-P intervals of atrial tachycardia with atrioventricular (A-V) block due to digitalis; and in the stimulus (St)-A intervals following electrical stimuli delivered to the atria at fast rates. Alternating Wenckebach periods of St-H and St-delta wave intervals in patients with the Wolff-Parkinson-White syndrome resulted from involvement of the Kent bundle itself, or of the atria as a proximal level common to distal longitudinally dissociated structures (Kent bundle and A-V node).

It is concluded that contrary to what is commonly believed alternating Wenckebach periods may be a tachycardia-dependent phenomenon occurring above, below or outside the A-V node and explaining a variety of spontaneous or electrically induced arrhythmias whose significance depends on the clinical setting in which they occur.     

Clinical predictors of left main coronary artery disease in high-risk patients with a first episode of non-ST-segment elevation acute coronary syndrome

INTRODUCTION AND OBJECTIVES: Risk stratification in non-ST-elevation acute coronary syndrome makes use of clinical variables that can identify patients at an increased risk of complications. Our objective was to identify clinical variables that predict significant stenosis (i.e., >50%) of the left main coronary artery in high-risk patients who have had a first episode of non-ST-elevation acute coronary syndrome but who do not have a history of coronary artery disease. METHODS: The study included 102 high-risk patients with no history of coronary artery disease who were admitted because of non-ST-elevation acute coronary syndrome. All underwent coronary angiography. Patients were divided into two groups: those with significant left main coronary artery stenosis (n=14) and those without (n=88). RESULTS: Univariate analysis showed that the variables significantly associated with left main coronary artery stenosis were age >65 years (57.1% vs 15.9%, P=.002), diabetes mellitus (71.4% vs 33.0%, P=.006), chronic renal failure (28.6% vs 5.7%, P=.019), left heart failure (71.4% vs 6.8%, P< .0001), cardiogenic shock (21.4% vs 1.1%, P=.008), and a low left ventricular ejection fraction at admission (49.9% [14.7%] vs 58.8% [9.9%], P=.044). In the multivariate analysis, the only significant independent predictor of left main coronary artery disease was left heart failure. CONCLUSIONS: The presence of left heart failure at initial assessment of high-risk patients with non-ST-elevation acute coronary syndrome but without a history of coronary artery disease could be a useful predictor of significant left main coronary artery disease.     

急性心肌梗死患者Ⅲ度房室传导阻滞与房室结动脉血供的关联性

目的 观察和分析急性心肌梗死(AMI)患者Ⅲ度房室传导阻滞(AVB)与房室结动脉血供的关系。方法 将入选的AMI患者,按是否并发Ⅲ度AVB分为两组:病例组为AMI并发Ⅲ度AVB的患者（n=35例）,对照组为AMI未并发Ⅲ度AVB的患者（n=215例）,通过观察梗死相关动脉并分析房室结动脉血供来源情况,分析AMI患者不同房室结动脉血供来源发生Ⅲ度AVB的几率,并观察AMI并发Ⅲ度AVB的患者,房室结动脉血运改善后Ⅲ度AVB恢复时间。结果 房室结动脉血供来源于右冠状动脉的右上降支动脉和回旋支的kugel’s动脉之一或二者双重血供。病例组患者,其房室结动脉血供仅来源于右冠状动脉的右上降支或回旋支的kugel’s动脉,无前降支来源,并且右冠状动脉较回旋支多见（P<0.01）。当梗死相关动脉得到再灌注,恢复血运后,AVB均恢复到窦性心律。结论 急性心肌梗死Ⅲ度AVB发生患者与其房室结动脉血供中断有关,恢复房室结动脉血供后AVB恢复窦性心律。     

Early atrial fibrillation during evolving myocardial infarction: a consequence of impaired left atrial perfusion

Seven of 214 patients (3%) with acute myocardial infarction (120 inferior and 94 anterior) developed atrial fibrillation within 3 hr of the onset of chest pain. All seven patients had an inferior infarction and in all seven the left circumflex artery was occluded proximal to the origin of its left atrial circumflex branch. In five patients this occlusion was acute and was the cause of inferior infarction and in the remaining two patients the occlusion was old and the inferior infarction was due to an acute occlusion of the right coronary artery that also supplied extensive collaterals to the previously occluded left circumflex artery. All seven patients also had impaired perfusion to the atrioventricular nodal artery, as evidenced by total occlusion proximal to its origin or by stenosis proximal to its origin associated with second- or third-degree atrioventricular block. In contrast, early atrial fibrillation did not occur in any of the 18 patients with inferior myocardial infarction due to acute occlusion of the distal left circumflex artery or in any of the five patients with inferior infarction due to acute occlusion of the proximal left circumflex artery if perfusion to the atrioventricular nodal artery was not impaired. Early atrial fibrillation did not occur in any of the 90 patients with inferior infarction due to acute occlusion of the right coronary artery, including 12 patients with occlusion proximal to the sinus nodal artery, but without coexistent occlusion of the left circumflex artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transient left ventricular apical ballooning or the tako-tsubo syndrome

Recently, Japanese authors have described a new clinical entity associating apical akidyskinesia and basal hyperkinesias without significant coronary artery disease under the name of the tako-tsubo syndrome. This syndrome is usually observed in elderly women and the clinical presentation is usually that of an acute coronary syndrome. The authors report 10 cases of patients investigated between June 2003 and August 2004. All patients were women with an average age of 66 +/- 15 years. Seven patients had chest pain on admission with, in three cases, signs of cardiac failure. In 8 patients, a causal factor was identified: emotional stress in 7 cases and anaphylactic shock in one case. All patients underwent coronary angiography and ventriculography which showed typical changes in left ventricular contractility without significant coronary disease. The peak CPK and troponin values were 222 +/- 115 UI/l and 3.32 +/- 1.50 microg/l, respectively. One patient died in cardiogenic shock. In the other cases, normalisation of wall motion was observed in the month following the onset of symptoms. One patient developed 3rd degree atrioventricular block and required implantation of a pacemaker. This clinical entity must be taken into consideration in elderly women with acute coronary syndromes.     

Bundle branch block in patients with chronic coronary artery disease: angiographic correlates and prognostic significance

The onset of bundle branch block during acute myocardial infarction is indicative of ischemia in the distribution of the left anterior descending coronary artery. However, whether patients with chronic coronary artery disease and bundle branch block have a predominance of left anterior descending artery lesions is not known. Similarly, the prognostic implications of bundle branch block have been studied primarily in the setting of acute myocardial infarction, and the independent prognostic implications of bundle branch block in patients with chronic coronary artery disease are not known. The electrocardiograms (ECGs) of 15,609 patients with chronic coronary artery disease who underwent coronary and left ventricular angiography as part of the Coronary Artery Surgery Study (CASS) were reviewed, and 522 patients with bundle branch block were identified. Patients with bundle branch block had both more extensive coronary artery disease and worse left ventricular function than did patients without bundle branch block. However, no particular location of coronary artery stenosis or left ventricular wall motion abnormality predominated in patients with bundle branch block. During a follow-up period of 4.9 +/- 1.3 years, 2,386 patients died. Actuarial probability of mortality at 2 years in patients with left bundle branch block was more than five times that in patients without bundle branch block (p less than 0.0001), and in patients with right bundle branch block the mortality rate was approximately twice that in patients without bundle branch block (p less than 0.0001). Stepwise Cox regression analysis showed that left bundle branch block, but not right bundle branch block, was a strong predictor of mortality, independent of degree of heart failure, extent of coronary disease and other variables (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)