Masaya Sugiura

A morphological study of the normally aging heart

A morphological examination of aging was performed on 141 normal hearts selected from a total of 972 consecutive autopsies on persons aged 60 years or over. The average heart weight was 270 ± 41 g. The circumference of the valvular ring was 99 ± 10 mm in the tricuspid valve, 68 ± 8 mm in the pulmonic valve, 83 ± 10 mm in the mitral valve, and 73 ± 7 mm in the aortic valve. The thickness of the tricuspid valve (anterior leaflet) was 0.9 ± 0.3 mm, pulmonic (anterior cusp) 0.4 ± 0.3 mm, mitral (anterior leaflet) 1.3 ± 0.6 mm, and aortic (posterior cusp) 1.0 ± 0.6 mm. Cardiac chamber volumes were as follows: 40 ± 14 mL in the right atrium, 22 ± 7 mL in the right ventricle, 37 ± 12 mL in the left atrium, and 7.3 ± 3.4 mL in the left ventricle. The circumference of the tricuspid ring was the largest. Left-sided valves were thicker than right-sides valves, and atrioventricular valves were thicker than semilunar valves. Cardiac chamber volumes were generally larger on the right side. Because this study was limited to hearts from persons aged 60 years or over, age-related changes were observed in only four parameters: (i) the circumference of the aortic valvular ring, (ii) the thickness of the aortic posterior cusp, (iii) the thickness of the pulmonic anterior cusp, and (iv) the volume of the left ventricle. With increasing age the aortic valvular ring dilated, the aortic posterior cusp and the pulmonic anterior cusp thickened, and the left ventricular volume diminished.A morphological examination of aging was performed on 141 normal hearts selected from a total of 972 consecutive autopsies on persons aged 60 years or over. The average heart weight was 270 ± 41 g. The circumference of the valvular ring was 99 ± 10 mm in the tricuspid valve, 68 ± 8 mm in the pulmonic valve, 83 ± 10 mm in the mitral valve, and 73 ± 7 mm in the aortic valve. The thickness of the tricuspid valve (anterior leaflet) was 0.9 ± 0.3 mm, pulmonic (anterior cusp) 0.4 ± 0.3 mm, mitral (anterior leaflet) 1.3 ± 0.6 mm, and aortic (posterior cusp) 1.0 ± 0.6 mm. Cardiac chamber volumes were as follows: 40 ± 14 mL in the right atrium, 22 ± 7 mL in the right ventricle, 37 ± 12 mL in the left atrium, and 7.3 ± 3.4 mL in the left ventricle. The circumference of the tricuspid ring was the largest. Left-sided valves were thicker than right-sides valves, and atrioventricular valves were thicker than semilunar valves. Cardiac chamber volumes were generally larger on the right side. Because this study was limited to hearts from persons aged 60 years or over, age-related changes were observed in only four parameters: (i) the circumference of the aortic valvular ring, (ii) the thickness of the aortic posterior cusp, (iii) the thickness of the pulmonic anterior cusp, and (iv) the volume of the left ventricle. With increasing age the aortic valvular ring dilated, the aortic posterior cusp and the pulmonic anterior cusp thickened, and the left ventricular volume diminished.

Double ventricular responses to a single atrial depolarization in a patient with dual AV nodal pathways

Electrophysiological study was performed in a patient with atrioventricular nodal reentrant tachycardia (AVNRT). Double ventricular responses through dual AV nodal pathways were observed by atrial extrastimulus technique followed by initiation of AVNRT. The drfference in conduction time between the slow and fast AV nodal pathways was longer than 320 msec. A ventricular extrastimulus delivered during sinus rhythm, which was not followed by ventriculoatrial conduction, also induced AVNRT. These findings indicated the presence of an antegrade critical delay and retrograde block in the slow AV nodal pathway, criteria necessary for the occurrence of a double ventricular response.

Pathological Aspects of Radiofrequency Catheter Ablation of the Canine Atrioventricular Node and Bundle of His

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first‐ and second‐degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2 4 weeks follow up) were various: normal in 2 dogs, mild PR prolongation (< 50%) in 2 dogs, first‐degree AV block (PR prolongation a 50%) in 2 dogs, second degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 μm). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed. Acta Pathol Jpn 41: 487–498, 1991.

Cardiomyopathy Characterized by Abnormal Accumulation of Desmin‐type Intermediate Filaments in Cardiac Muscle Fibers: A Case Report and Review of the Literature

A 42 year old Japanese male, who had been suffering from congestive heart failure and electrocardiographic abnormalities (A V block, intraventricular conduction disturbance, ventricular tachycardia), died after a clinical course of 2 years and 1 month. Macroscopic investigation revealed dilation of the left ventricle and thickening of the right ventricular wall. The unique finding in this case was a circumferential fibrous scar in the median circular layer and outer oblique layer of the left ventricular wall. Biopsy and autopsy materials revealed diffuse loss of myofibrils in the central zone of cardiac muscle fibers, and replacement with aniline blue positive homogeneous material (17–35% of the area of one muscle fiber). Electron microscopy revealed abnormal accumulation of fine filamentous material (7.5–25 nm in diameter), which was immunohisto‐chemically proved to be desmin type intermediate filament. Moreover, sarcoplasmic reticulum like material was detected in the degenerated area. At autopsy, degeneration was detected all over the heart. The ventricular muscle fibers were more severely affected than the atrial muscle fibers. The conduction system was also affected, in some parts more severely than the surrounding ordinary muscle fibers. The pathogenesis of this disorder remains to be clarified. Acta Pathol Jpn 39: 266–273, 1989.

Runaway Pacemaker. A Case Report with a Runaway Rate of 2100 ppm

A case of runaway pulse generator is described. A Vitalith C‐23 developed runaway on the 13th postoperative day, without any preceding changes in the rate or amplitude of the pulse generator spike. The rate of runaway was 2100 pulses per minute (ppm), one of the highest rates ever reported. The ventricle was not captured by the runaway pulse generator, but was paced effectively by a temporary demand pacemaker (Medtronic 5880A) which was left in case of displacement of the implanted pacing lead. The reasons why the temporary pacemaker was not inhibited are discussed.

Acute Reversible Myocardial Infarction after Blood Transfusion in the Aged

老年者の出血, 手術に際し輸血により急激にヘマトクリットを上昇させた際, 一過性に急性心筋梗塞様心電図を示したが, 剖検上心筋梗塞の認められない7例を示した.基礎疾患は消化器癌4例, 胃潰瘍2例, 偽膜性大腸炎1例であり, 心電図は異常Qと共にST上昇冠性Tと典型的心筋梗塞所見を示したが, その持続は2-7日と短かく輸血前の所見に回復した. ヘマトクリットは800乃至1800mlの輸血により28.9から47.9と上昇し, 血管内凝固症候群を5例に認めた. GOTは1例を除き正常範囲の上昇であった.病理所見は新鮮例に壁在血栓から thebesius 静脈系の血栓とその周囲の限局性小壊死巣を認め, 陳旧例では血栓の吸収, 間質線維化, 心筋の軽度脱落と網状線維化等修復像を認めた. これ等臨床及び病理所見から本症候群に対し reversible myocardial infarction の概念を提唱し, その成因として血管内凝固症候群, ヘマトクリット上昇の関与を推定した.

Evaluation of radionuclide angiocardiography (RNA) in patients with myocardial infarction: A camparison with postmortem findings

Radionuclide angiocardiograpy (RNA)における局所壁運動による梗塞診断率を剖検所見と対比して求めた. RNAの有病正診率は84.1%,無病正診率58.8%,総合正診率70.1%であつた.梗塞のない症例においても,壁運動異常が半数に認められ,特に広範囲壁運動異常を認めうものが多かつた.広範囲壁運動異常を示すものには,心筋梗塞症以外に, cardiacamyloidosisやうつ血型心筋症などの心疾患が認められた.心筋梗塞症例で, LVEF 30%未満のものでは,心臓死が87%に認められ,予後は9.3カ月と他の群に比し有意に短かつた. RNAは心筋梗塞の部位,心室瘤の有無,心機能を把握できるばかりでなく,安静時LVEFは心筋梗塞の予後の推定に有用であると思われた.

[Prognosis of the lower extremity function with aging in patients with postapoplectic hemiplegia and factors interfering with rehabilitation--especially in octogenarians].

加齢に伴う脳卒中後片麻痺患者の下肢機能の予後とリハビリテーション (以下リハと略す) 阻害因子などを知るために, 脳CTスキャン上1側の内包後脚のみに大きさが固定した長径15mm以下 (実物大計算値) の責任病巣がみられた98例 (43～87歳) を検討し次の結論を得た.I. 下肢機能の予後: (1)加齢に伴い, 独歩自立は直線的に減少し (p<0.01), 一方歩行不能は漸増し (p<0.05) 80歳代で急増傾向がみられ, 年齢が強く関与していると考えられる. (2)独歩自立の質的内容では, 加齢に伴い, 杖使用歩行は直線的に増加し (p<0.01), 一方屋外歩行自立は漸減し (p<0.05), 80歳代では前者は全例となり後者は急減傾向がみられた. 従って80歳代の一般論的なリハ目標は, 家庭復帰と屋内ADL自立であると考えられる. (3)脳病巣の部位と大きさでは部位のみが関連し, 脳病巣が内包後脚後半部にある症例は大きさに関係なく予後が悪かった (p<0.05). (4)脳出血, 脳梗塞の病型及び左右片麻痺による予後の差はみられなかった.II. リハ阻害因子: (1)出現頻度が年齢と相関するものは, 健側筋力低下, 意欲低下, 尿失禁, 痴呆の4つで (各々p<0.05), 前者2つは80歳代で, 後者2つは70歳代で増加した. (2)80歳代の下肢機能の予後と関連があるものは, 健側筋力低下, 意欲低下, 尿失禁の3つで (各々p<0.05), 痴呆は相関の傾向がみられるのみであった. (3)前記の4つのリハ阻害因子が独歩自立と歩行不能のどちらに関連が強いかをみると, 前者3つは歩行不能と関連が強く (各々p<0.01) 痴呆は独歩自立とのみ負の関連がみられた (p<0.05). (4)80歳代の健側筋力は臥床により急速且容易に低下し回復が容易でないことが観察されることから, 可及的早期にリハを開始することに特に留意すべきである.以上の結論を得たが, 脳卒中後片麻痺患者の下肢機能の予後は, 年齢, 脳病巣の部位やリハ阻害因子などが複雑に絡みあった上に成り立っており, これらの因子が単独で予後を規定することは極めて稀であると考えられる.

Congenital numeral anomalies of the semilunar valves in the aged.

60歳以上の老年者の連続剖検3,000例中に先天性半月弁数異常を計32例 (1.06%) に見出した. そのうち大動脈二尖弁10例 (0.33%), 大動脈四尖弁3例 (0.1%), 肺動脈二尖弁2例 (0.07%), 動脈四尖弁17例 (0.57%) であった. 大動脈二尖弁のうち石灰化大動脈弁狭窄を呈したのは7例で, 弁膜の形態は左右尖からそれぞれ左右冠状動脈の出るもの8例, 両冠状動脈が1つの洞より出るもの2例であった. 大動脈四尖弁は3例とも臨床診断されておらず, 形態的には第4尖は他よりも小さく, 右冠尖と無冠尖の間に存在した.肺動脈二尖弁2例中1例に拡張期雑音を聴取し, 形態的には左右尖が合一していた. 肺動脈四尖弁は最も高頻度で心雑音は9例に記載があるが本症は診断されなかった. 四尖弁の形態は四尖とも同大のもの3例で, 他は第4尖が小さく, 右尖左尖間に入るもの6例, 左尖前尖間7例, 前尖右尖間1例であった.

Effect of Right Ventricular Pacing Rate on the Asynchronous Contraction of the Ventricles Studied by a Phase Analysis of Multigated RN Angiocardiogram

The effect of the rate of right ventricular, endocardial pacing on the asynchronous contraction of the ventricles was studied by the phase analysis of the regional volume curves of the right and left ventricles on multigated, equilibrium RN angiocardiogram in ten adult control subjects (mean age, 38.0 years) and eight aged patients (mean age, 77.8 years) receiving ventricular demand pacemaker.